claude-prompting-best-practices changedbuild-with-claude/prompt-engineering/claude-prompting-best-practices
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1111* **Migration considerations** last, for prompts moving from earlier generations.
1212
1313<Tip>
14 For an overview of model capabilities, see the [models overview](https://platform.claude.com/docs/en/models/overview). For Claude Fable 5.1 capabilities and API changes, see [What's new in Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/whats-new-fable-5-1). For migration guidance, see the [Migration guide](https://platform.claude.com/docs/en/about-claude/models/migration-guide). For Claude Opus 5.5, see [What's new in Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/whats-new-opus-5-5). For Claude Sonnet 5.5, see [What's new in Claude Sonnet 5.5](https://platform.claude.com/docs/en/models/sonnet-5-5/whats-new-sonnet-5-5). For Claude Haiku 5.5, see [What's new in Claude Haiku 5.5](https://platform.claude.com/docs/en/models/haiku-5-5/whats-new-haiku-5-5).
14 For an overview of model capabilities, see the [models overview](https://platform.claude.com/docs/en/models/overview). For Claude Fable 5.1 capabilities and API changes, see [What’s new in Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/whats-new-fable-5-1). For migration guidance, see the [Migration guide](https://platform.claude.com/docs/en/about-claude/models/migration-guide). For Claude Opus 5.5, see [What’s new in Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/whats-new-opus-5-5). For Claude Sonnet 5.5, see [What’s new in Claude Sonnet 5.5](https://platform.claude.com/docs/en/models/sonnet-5-5/whats-new-sonnet-5-5). For Claude Haiku 5.5, see [What’s new in Claude Haiku 5.5](https://platform.claude.com/docs/en/models/haiku-5-5/whats-new-haiku-5-5).
1515</Tip>
1616
1717## Model-specific guidance
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1818
1919Each of these models has its own prompting page. Read the one for your model first, then the techniques that follow.
2020
21| Model | Guide | What's different |
21| Model | Guide | What’s different |
2222| -------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
2323| Claude Fable 5.1 and Claude Mythos 5.1 | [Prompting Claude Fable 5.1](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-fable-5-1) | Differences from Claude Fable 5: effort levels, finishing long tasks, user-facing progress updates, passing thinking blocks back unchanged, tool-call batching in agent loops, search triggering at low effort, formatting, and writing density. |
2424| Claude Fable 5 and Claude Mythos 5 | [Prompting Claude Fable 5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-fable-5) | Differences from Claude Opus 4.8: effort levels, instruction following, long-run progress claims, memory systems, and the `reasoning_extraction` refusal category. |
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3939
4040Think of Claude as a brilliant but new employee who lacks context on your norms and workflows. The more precisely you explain what you want, the better the result.
4141
42**Key test:** Show your prompt to a colleague with minimal context on the task and ask them to follow it. If they'd be confused, Claude will be too.
42**Key test:** Show your prompt to a colleague with minimal context on the task and ask them to follow it. If they’d be confused, Claude will be too.
4343
4444* Be specific about the output format and constraints you want.
4545* Provide instructions as sequential steps using numbered lists or bullet points when the order or completeness of steps matters.
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8080
8181### Use examples effectively
8282
83Examples are one of the most reliable ways to steer Claude's output format, tone, and structure. A few well-crafted examples (known as few-shot or multishot prompting) improve accuracy and consistency.
83Examples are one of the most reliable ways to steer Claude’s output format, tone, and structure. A few well-crafted examples (known as few-shot or multishot prompting) improve accuracy and consistency.
8484
8585When adding examples, make them:
8686
8787* **Relevant:** Mirror your actual use case closely.
88* **Diverse:** Cover edge cases and vary enough that Claude doesn't pick up unintended patterns.
88* **Diverse:** Cover edge cases and vary enough that Claude doesn’t pick up unintended patterns.
8989* **Structured:** Wrap examples in `<example>` tags (multiple examples in `<examples>` tags) so Claude can distinguish them from instructions.
9090
9191<Tip>
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103103
104104### Give Claude a role
105105
106Setting a role in the system prompt focuses Claude's behavior and tone for your use case. Even a single sentence makes a difference:
106Setting a role in the system prompt focuses Claude’s behavior and tone for your use case. Even a single sentence makes a difference:
107107
108108<CodeGroup>
109109 ```bash cURL
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319319
320320### Communication style and verbosity
321321
322Claude's latest models have a more concise and natural communication style compared to previous models:
322Claude’s latest models have a more concise and natural communication style compared to previous models:
323323
324324* **More direct and grounded:** Provides fact-based progress reports rather than self-celebratory updates
325325* **More conversational:** Slightly more fluent and colloquial, less machine-like
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331331After completing a task that involves tool use, provide a quick summary of the work you've done.
332332```
333333
334Claude Opus 5 is an exception on verbosity: its default user-facing responses run longer than prior models', and raising or lowering [effort](https://platform.claude.com/docs/en/build-with-claude/effort) does not reliably change visible response length. Prompt explicitly for conciseness instead. See [Prompting Claude Opus 5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5#response-length-and-verbosity) for a sample instruction. Claude Fable 5.1 has the opposite tendency during agentic work: it writes fewer user-facing updates between tool calls. Ask for progress text explicitly, and remove any instruction telling it to keep that text brief. See [Ask for user-facing progress updates](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-fable-5-1#ask-for-user-facing-progress-updates).
334Claude Opus 5 is an exception on verbosity: its default user-facing responses run longer than prior models’, and raising or lowering [effort](https://platform.claude.com/docs/en/build-with-claude/effort) does not reliably change visible response length. Prompt explicitly for conciseness instead. See [Prompting Claude Opus 5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5#response-length-and-verbosity) for a sample instruction. Claude Fable 5.1 has the opposite tendency during agentic work: it writes fewer user-facing updates between tool calls. Ask for progress text explicitly, and remove any instruction telling it to keep that text brief. See [Ask for user-facing progress updates](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-fable-5-1#ask-for-user-facing-progress-updates).
335335
336336### Control the format of responses
337337
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339339
3403401. **Tell Claude what to do instead of what not to do**
341341
342 * Instead of: "Do not use markdown in your response"
343 * Try: "Your response should be composed of smoothly flowing prose paragraphs."
342 * Instead of: “Do not use markdown in your response”
343 * Try: “Your response should be composed of smoothly flowing prose paragraphs.”
344344
3453452. **Use XML format indicators**
346346
347 * Try: "Write the prose sections of your response in \<smoothly\_flowing\_prose\_paragraphs> tags."
347 * Try: “Write the prose sections of your response in \<smoothly\_flowing\_prose\_paragraphs> tags.”
348348
3493493. **Match your prompt style to the output you want**
350350
351 The formatting style used in your prompt might influence Claude's response style. If you are still experiencing steerability issues with output formatting, try matching your prompt style to the output style you want as closely as possible. For example, removing markdown from your prompt can reduce the volume of markdown in the output.
351 The formatting style used in your prompt might influence Claude’s response style. If you are still experiencing steerability issues with output formatting, try matching your prompt style to the output style you want as closely as possible. For example, removing markdown from your prompt can reduce the volume of markdown in the output.
352352
3533534. **Use detailed prompts for specific formatting preferences**
354354
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380380
381381### LaTeX output
382382
383Claude's latest models default to LaTeX for mathematical expressions, equations, and technical explanations. If you prefer plain text, add the following instructions to your prompt:
383Claude’s latest models default to LaTeX for mathematical expressions, equations, and technical explanations. If you prefer plain text, add the following instructions to your prompt:
384384
385385```text Sample prompt wrap
386386Format your response in plain text only. Do not use LaTeX, MathJax, or any markup
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390390
391391### Document creation
392392
393Claude's latest models create presentations, animations, and visual documents with strong instruction following, and usually produce usable output on the first try.
393Claude’s latest models create presentations, animations, and visual documents with strong instruction following, and usually produce usable output on the first try.
394394
395395For best results with document creation:
396396
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408408<Accordion title="Controlling output formatting">
409409 Prefills have been used to force specific output formats such as JSON/YAML, classification, and similar patterns where the prefill constrains Claude to a particular structure.
410410
411 **Migration:** The [structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs) feature is designed specifically to constrain Claude's responses to follow a given schema. Try asking the model to conform to your output structure first, as newer models can reliably match complex schemas when told to, especially if implemented with retries. For classification tasks, use either tools with an enum field containing your valid labels or structured outputs.
411 **Migration:** The [structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs) feature is designed specifically to constrain Claude’s responses to follow a given schema. Try asking the model to conform to your output structure first, as newer models can reliably match complex schemas when told to, especially if implemented with retries. For classification tasks, use either tools with an enum field containing your valid labels or structured outputs.
412412</Accordion>
413413
414414<Accordion title="Eliminating preambles">
415415 Prefills such as `Here is the requested summary:\n` were used to skip introductory text.
416416
417 **Migration:** Use direct instructions in the system prompt: "Respond directly without preamble. Do not start with phrases like 'Here is...', 'Based on...', etc." Alternatively, direct the model to output within XML tags, use structured outputs, or use tool calling. If the occasional preamble slips through, strip it in post-processing.
417 **Migration:** Use direct instructions in the system prompt: “Respond directly without preamble. Do not start with phrases like ‘Here is...’, ‘Based on...’, etc.” Alternatively, direct the model to output within XML tags, use structured outputs, or use tool calling. If the occasional preamble slips through, strip it in post-processing.
418418</Accordion>
419419
420420<Accordion title="Avoiding bad refusals">
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426426<Accordion title="Continuations">
427427 Prefills were used to continue partial completions, resume interrupted responses, or extend a previous generation from where it ended.
428428
429 **Migration:** Move the continuation to the user message, and include the final text from the interrupted response: "Your previous response was interrupted and ended with \`\[previous\_response]\`. Continue from where you left off." If this is part of error-handling or incomplete-response-handling and there is no UX penalty, retry the request.
429 **Migration:** Move the continuation to the user message, and include the final text from the interrupted response: “Your previous response was interrupted and ended with \`\[previous\_response]\`. Continue from where you left off.” If this is part of error-handling or incomplete-response-handling and there is no UX penalty, retry the request.
430430</Accordion>
431431
432432<Accordion title="Context hydration and role consistency">
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439439
440440### Tool usage
441441
442Claude's latest models are trained for precise instruction following and benefit from explicit direction to use specific tools. If you say "can you suggest some changes," Claude will sometimes provide suggestions rather than implementing them, even if making changes might be what you intended. To learn how to define tools and troubleshoot tool triggering, see [Tool use with Claude](https://platform.claude.com/docs/en/agents-and-tools/tool-use/overview).
442Claude’s latest models are trained for precise instruction following and benefit from explicit direction to use specific tools. If you say “can you suggest some changes,” Claude will sometimes provide suggestions rather than implementing them, even if making changes might be what you intended. To learn how to define tools and troubleshoot tool triggering, see [Tool use with Claude](https://platform.claude.com/docs/en/agents-and-tools/tool-use/overview).
443443
444444For Claude to take action, be more explicit:
445445
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485485</do_not_act_before_instructions>
486486```
487487
488Claude Opus 4.5 and Claude Opus 4.6 are also more responsive to the system prompt than previous models. If your prompts were designed to reduce undertriggering on tools or skills, these models might now overtrigger. The fix is to soften any aggressive language. Where you might have said "CRITICAL: You MUST use this tool when...," you can use more normal prompting such as "Use this tool when..." instead.
488Claude Opus 4.5 and Claude Opus 4.6 are also more responsive to the system prompt than previous models. If your prompts were designed to reduce undertriggering on tools or skills, these models might now overtrigger. The fix is to soften any aggressive language. Where you might have said “CRITICAL: You MUST use this tool when...,” you can use more normal prompting such as “Use this tool when...” instead.
489489
490490### Optimize parallel tool calling
491491
492Claude's latest models run independent tool calls in parallel. These models:
492Claude’s latest models run independent tool calls in parallel. These models:
493493
494494* Run multiple speculative searches during research
495495* Read several files at once to build context faster
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523523
524524Claude Opus 4.6 does more upfront exploration than previous models, especially at higher [`effort`](https://platform.claude.com/docs/en/build-with-claude/effort) settings. This initial work often helps to optimize the final results, but the model might gather extensive context or pursue multiple threads of research without being prompted. If your prompts previously encouraged the model to be more thorough, you should tune that guidance for Claude Opus 4.6:
525525
526* **Replace blanket defaults with more targeted instructions.** Instead of "Default to using \[tool]," add guidance such as "Use \[tool] when it would enhance your understanding of the problem."
527* **Remove over-prompting.** Tools that undertriggered in previous models are likely to trigger appropriately now. Instructions such as "If in doubt, use \[tool]" cause overtriggering.
526* **Replace blanket defaults with more targeted instructions.** Instead of “Default to using \[tool],” add guidance such as “Use \[tool] when it would enhance your understanding of the problem.”
527* **Remove over-prompting.** Tools that undertriggered in previous models are likely to trigger appropriately now. Instructions such as “If in doubt, use \[tool]” cause overtriggering.
528528* **Use effort as a fallback.** If Claude continues to be overly aggressive, use a lower setting for `effort`.
529529
530530In some cases, Claude Opus 4.6 might think extensively, which can inflate thinking tokens and slow down responses. If this behavior is undesirable, you can add explicit instructions to constrain its reasoning, or you can lower the `effort` setting to reduce overall thinking and token usage.
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540540
541541### Leverage thinking and interleaved thinking capabilities
542542
543Claude's latest models offer thinking capabilities that can be especially helpful for tasks involving reflection after tool use or complex multistep reasoning. You can guide its initial or interleaved thinking for better results.
543Claude’s latest models offer thinking capabilities that can be especially helpful for tasks involving reflection after tool use or complex multistep reasoning. You can guide its initial or interleaved thinking for better results.
544544
545Claude 4.6 and later models and Claude Mythos Preview use [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) (`thinking: {type: "adaptive"}`), where Claude dynamically determines when and how much to think. On Claude Fable 5.1, Claude Mythos 5.1, Claude Fable 5, Claude Mythos 5, and Claude Opus 5.5, thinking is always on and adaptive thinking is the only mode. Claude calibrates its thinking based on two factors: the `effort` parameter and query complexity. Higher effort elicits more thinking, and more complex queries do the same. On easier queries that don't require thinking, the model responds directly. In internal evaluations, adaptive thinking reliably drives better performance than extended thinking. Consider moving to adaptive thinking.
545Claude 4.6 and later models and Claude Mythos Preview use [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) (`thinking: {type: "adaptive"}`), where Claude dynamically determines when and how much to think. On Claude Fable 5.1, Claude Mythos 5.1, Claude Fable 5, Claude Mythos 5, and Claude Opus 5.5, thinking is always on and adaptive thinking is the only mode. Claude calibrates its thinking based on two factors: the `effort` parameter and query complexity. Higher effort elicits more thinking, and more complex queries do the same. On easier queries that don’t require thinking, the model responds directly. In internal evaluations, adaptive thinking reliably drives better performance than extended thinking. Consider moving to adaptive thinking.
546546
547547Use adaptive thinking for workloads that require agentic behavior such as multistep tool use, complex coding tasks, and long-horizon agent loops. Older models use manual [extended thinking](https://platform.claude.com/docs/en/build-with-claude/extended-thinking) with `budget_tokens`; see the [per-model configuration table](https://platform.claude.com/docs/en/build-with-claude/thinking-troubleshooting#supported-models) for which configuration each model accepts.
548548
549You can guide Claude's thinking behavior:
549You can guide Claude’s thinking behavior:
550550
551551```text Example prompt wrap
552552After receiving tool results, carefully reflect on their quality and determine optimal
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554554information, and then take the best next action.
555555```
556556
557The triggering behavior for adaptive thinking is promptable. If you find the model thinking more often than you'd like, which can occur with large or complex system prompts, add guidance to steer it:
557The triggering behavior for adaptive thinking is promptable. If you find the model thinking more often than you’d like, which can occur with large or complex system prompts, add guidance to steer it:
558558
559559```text Sample prompt wrap
560560Thinking adds latency and should only be used when it will meaningfully improve
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773773 ```
774774</CodeGroup>
775775
776If you are not using extended thinking, you don't need to add a `thinking` parameter. On Claude Opus 4.6 through Claude Opus 4.8 and Claude Sonnet 4.6, thinking is off when you omit the `thinking` parameter. On Claude Opus 5, Claude Sonnet 5.5, Claude Sonnet 5, and Claude Haiku 5.5, thinking is on by default when you omit the `thinking` parameter, so a response can begin with `thinking` blocks. Select content blocks by `type` rather than by position, and leave room in `max_tokens` for thinking. On Claude Opus 5 and Claude Haiku 5.5, you can disable it only at effort `high` or lower. On Claude Sonnet 5.5, the lowest thinking setting is `between_tools`, accepted at effort `high` or lower. On Claude Fable 5.1, Claude Mythos 5.1, Claude Fable 5, Claude Mythos 5, and Claude Opus 5.5, thinking is always on, regardless of whether you set the `thinking` parameter.
776If you are not using extended thinking, you don’t need to add a `thinking` parameter. On Claude Opus 4.6 through Claude Opus 4.8 and Claude Sonnet 4.6, thinking is off when you omit the `thinking` parameter. On Claude Opus 5, Claude Sonnet 5.5, Claude Sonnet 5, and Claude Haiku 5.5, thinking is on by default when you omit the `thinking` parameter, so a response can begin with `thinking` blocks. Select content blocks by `type` rather than by position, and leave room in `max_tokens` for thinking. On Claude Opus 5 and Claude Haiku 5.5, you can disable it only at effort `high` or lower. On Claude Sonnet 5.5, the lowest thinking setting is `between_tools`, accepted at effort `high` or lower. On Claude Fable 5.1, Claude Mythos 5.1, Claude Fable 5, Claude Mythos 5, and Claude Opus 5.5, thinking is always on, regardless of whether you set the `thinking` parameter.
777777
778* **Prefer general instructions over prescriptive steps.** A prompt such as "think thoroughly" often produces better reasoning than a hand-written step-by-step plan. Claude's reasoning frequently exceeds what a human would prescribe.
778* **Prefer general instructions over prescriptive steps.** A prompt such as “think thoroughly” often produces better reasoning than a hand-written step-by-step plan. Claude’s reasoning frequently exceeds what a human would prescribe.
779779* **Multishot examples work with thinking.** Worked examples in your prompt shape how Claude approaches similar problems in its own thinking blocks. Present each example as a problem, the method to apply, and the expected answer.
780780* **Manual chain-of-thought (CoT) prompting as a fallback.** When thinking is off, you can still encourage step-by-step reasoning by asking Claude to think through the problem before it answers, and to put the final answer in `<answer>` tags so you can extract it. On Claude Fable 5.1, Claude Fable 5, Claude Opus 5.5, Claude Opus 5, and Claude Sonnet 5.5, rely on thinking instead, at a lower [effort](https://platform.claude.com/docs/en/build-with-claude/effort) level if cost or latency matters: a prompt that asks the model to write out its reasoning, for example in `<thinking>` tags, may be declined. See [Keep reasoning in thinking blocks](https://platform.claude.com/docs/en/build-with-claude/refusals-and-fallback#keep-reasoning-in-thinking-blocks).
781* **Ask Claude to self-check.** Append something like "Before you finish, verify your answer against \[test criteria]." This catches errors reliably, especially for coding and math. Claude Opus 5 is the exception: it verifies its own work well without explicit instruction, and verification instructions carried over from prompts tuned for earlier models can cause over-verification, adding tokens and latency. On Claude Opus 5, remove these instructions rather than rewriting them. See [Task scope and over-verification](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5#task-scope-and-over-verification).
781* **Ask Claude to self-check.** Append something like “Before you finish, verify your answer against \[test criteria].” This catches errors reliably, especially for coding and math. Claude Opus 5 is the exception: it verifies its own work well without explicit instruction, and verification instructions carried over from prompts tuned for earlier models can cause over-verification, adding tokens and latency. On Claude Opus 5, remove these instructions rather than rewriting them. See [Task scope and over-verification](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5#task-scope-and-over-verification).
782782
783783<Note>
784 When extended thinking is disabled, Claude Opus 4.5 is particularly sensitive to the word "think" and its variants. Consider using alternatives such as "consider," "evaluate," or "reason through" in those cases.
784 When extended thinking is disabled, Claude Opus 4.5 is particularly sensitive to the word “think” and its variants. Consider using alternatives such as “consider,” “evaluate,” or “reason through” in those cases.
785785</Note>
786786
787787<Info>
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792792
793793### Long-horizon reasoning and state tracking
794794
795Claude's latest models handle long-horizon reasoning tasks with strong state tracking. Claude maintains orientation across extended sessions by focusing on incremental progress, making steady advances on a few things at a time rather than attempting everything at once. This capability especially emerges over multiple context windows or task iterations, where Claude can work on a complex task, save the state, and continue with a fresh context window.
795Claude’s latest models handle long-horizon reasoning tasks with strong state tracking. Claude maintains orientation across extended sessions by focusing on incremental progress, making steady advances on a few things at a time rather than attempting everything at once. This capability especially emerges over multiple context windows or task iterations, where Claude can work on a complex task, save the state, and continue with a fresh context window.
796796
797797#### Context awareness and multiwindow workflows
798798
799Claude Sonnet 5, Claude Sonnet 4.6, Claude Sonnet 4.5 (deprecated), and Claude Haiku 4.5 feature [context awareness](https://platform.claude.com/docs/en/build-with-claude/context-windows#context-awareness), which lets the model track its remaining context window (that is, its "token budget") throughout a conversation. This allows Claude to run tasks and manage context more effectively based on how much space it has to work.
799Claude Sonnet 5, Claude Sonnet 4.6, Claude Sonnet 4.5 (deprecated), and Claude Haiku 4.5 feature [context awareness](https://platform.claude.com/docs/en/build-with-claude/context-windows#context-awareness), which lets the model track its remaining context window (that is, its “token budget”) throughout a conversation. This allows Claude to run tasks and manage context more effectively based on how much space it has to work.
800800
801801**Managing context limits:**
802802
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820820
8218211. **Use a different prompt for the very first context window:** Use the first context window to set up a framework (write tests, create setup scripts), then use future context windows to iterate on a todo-list.
822822
8232. **Have the model write tests in a structured format:** Ask Claude to create tests before starting work and keep track of them in a structured format (for example, `tests.json`). This leads to better long-term ability to iterate. Remind Claude of the importance of tests: "It is unacceptable to remove or edit tests because this could lead to missing or buggy functionality."
8232. **Have the model write tests in a structured format:** Ask Claude to create tests before starting work and keep track of them in a structured format (for example, `tests.json`). This leads to better long-term ability to iterate. Remind Claude of the importance of tests: “It is unacceptable to remove or edit tests because this could lead to missing or buggy functionality.”
824824
8258253. **Set up convenience tools:** Encourage Claude to create setup scripts (for example, `init.sh`) to gracefully start servers and run test suites and linters. This prevents repeated work when continuing from a fresh context window.
826826
8274. **Choose between starting fresh and compacting:** When a context window is cleared, consider starting with a brand new context window rather than using compaction. Claude's latest models are extremely effective at discovering state from the local filesystem. In some cases, you might want to take advantage of this over compaction. Be prescriptive about how it should start:
8274. **Choose between starting fresh and compacting:** When a context window is cleared, consider starting with a brand new context window rather than using compaction. Claude’s latest models are extremely effective at discovering state from the local filesystem. In some cases, you might want to take advantage of this over compaction. Be prescriptive about how it should start:
828828
829 * "Call pwd; you can only read and write files in this directory."
830 * "Review progress.txt, tests.json, and the git logs."
831 * "Manually run through a fundamental integration test before moving on to implementing new features."
829 * “Call pwd; you can only read and write files in this directory.”
830 * “Review progress.txt, tests.json, and the git logs.”
831 * “Manually run through a fundamental integration test before moving on to implementing new features.”
832832
8338335. **Provide verification tools:** As the length of autonomous tasks grows, Claude needs to verify correctness without continuous human feedback. Tools that let Claude verify UI work are helpful, such as the [computer use tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool), the [browser use tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/browser-use-tool), or a browser automation MCP server.
834834
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845845
846846* **Use structured formats for state data:** When tracking structured information (such as test results or task status), use JSON or other structured formats to make schema requirements explicit to Claude.
847847* **Use unstructured text for progress notes:** Freeform progress notes work well for tracking general progress and context.
848* **Use git for state tracking:** Git provides a log of what's been done and checkpoints that can be restored. Claude's latest models perform especially well in using git to track state across multiple sessions.
848* **Use git for state tracking:** Git provides a log of what’s been done and checkpoints that can be restored. Claude’s latest models perform especially well in using git to track state across multiple sessions.
849849* **Emphasize incremental progress:** Explicitly ask Claude to keep track of its progress and focus on incremental work.
850850
851851<Accordion title="Example: State tracking">
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896896
897897### Research and information gathering
898898
899Claude's latest models can find and synthesize information from multiple sources effectively. For optimal research results:
899Claude’s latest models can find and synthesize information from multiple sources effectively. For optimal research results:
900900
9019011. **Provide clear success criteria:** Define what constitutes a successful answer to your research question.
902902
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916916
917917### Subagent orchestration
918918
919Claude's latest models orchestrate subagents natively. These models can recognize when tasks would benefit from delegating work to specialized subagents and do so proactively without requiring explicit instruction.
919Claude’s latest models orchestrate subagents natively. These models can recognize when tasks would benefit from delegating work to specialized subagents and do so proactively without requiring explicit instruction.
920920
921921To take advantage of this behavior:
922922
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9249242. **Let Claude orchestrate naturally:** Claude delegates appropriately without explicit instruction.
9259253. **Watch for overuse:** Claude Opus 4.6 has a strong tendency to use subagents and might spawn them in situations where a simpler, direct approach would suffice. For example, the model might spawn subagents for code exploration when a direct grep call is faster and sufficient. Claude Opus 5 also delegates to subagents more readily than prior models; see [Controlling subagent spawning](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5#controlling-subagent-spawning) for guidance and a sample damping prompt.
926926
927If you're seeing excessive subagent use, add explicit guidance about when subagents are and aren't warranted:
927If you’re seeing excessive subagent use, add explicit guidance about when subagents are and aren’t warranted:
928928
929929```text Sample prompt for subagent usage wrap
930930Use subagents when tasks can run in parallel, require isolated context, or involve
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941941
942942### Reduce file creation in agentic coding
943943
944Claude's latest models might sometimes create new files for testing and iteration purposes, particularly when working with code. This approach allows Claude to use files, especially Python scripts, as a 'temporary scratchpad' before saving its final output. Using temporary files can improve outcomes particularly for agentic coding use cases.
944Claude’s latest models might sometimes create new files for testing and iteration purposes, particularly when working with code. This approach allows Claude to use files, especially Python scripts, as a ‘temporary scratchpad’ before saving its final output. Using temporary files can improve outcomes particularly for agentic coding use cases.
945945
946If you'd prefer to minimize the number of new files left behind, you can instruct Claude to clean up after itself:
946If you’d prefer to minimize the number of new files left behind, you can instruct Claude to clean up after itself:
947947
948948```text Sample prompt wrap
949949If you create any temporary new files, scripts, or helper files for iteration, clean up
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952952
953953### Overeagerness
954954
955Claude Opus 4.5 and Claude Opus 4.6 have a tendency to overengineer by creating extra files, adding unnecessary abstractions, or building in flexibility that wasn't requested. If you're seeing this undesired behavior, add specific guidance to keep solutions minimal.
955Claude Opus 4.5 and Claude Opus 4.6 have a tendency to overengineer by creating extra files, adding unnecessary abstractions, or building in flexibility that wasn’t requested. If you’re seeing this undesired behavior, add specific guidance to keep solutions minimal.
956956
957957For example:
958958
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998998
999999### Minimizing hallucinations in agentic coding
10001000
1001Claude's latest models are less prone to hallucinations and give more accurate, grounded, intelligent answers based on the code. To encourage this behavior even more and minimize hallucinations:
1001Claude’s latest models are less prone to hallucinations and give more accurate, grounded, intelligent answers based on the code. To encourage this behavior even more and minimize hallucinations:
10021002
10031003```text Sample prompt wrap
10041004<investigate_before_answering>
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10161016
10171017Claude Opus 4.5 and Claude Opus 4.6 have improved vision capabilities compared to previous Claude models. They perform better on image processing and data extraction tasks, particularly when there are multiple images present in context. These improvements carry over to computer use, where the models can more reliably interpret screenshots and UI elements. You can also use these models to analyze videos by breaking them up into frames.
10181018
1019One technique that has proven effective to further boost performance is to give Claude a crop tool or [agent skill](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/overview). Testing has shown consistent uplift on image evaluations when Claude is able to "zoom" in on relevant regions of an image. Anthropic has created a [recipe for the crop tool](https://platform.claude.com/cookbook/multimodal-crop-tool).
1019One technique that has proven effective to further boost performance is to give Claude a crop tool or [agent skill](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/overview). Testing has shown consistent uplift on image evaluations when Claude is able to “zoom” in on relevant regions of an image. Anthropic has created a [recipe for the crop tool](https://platform.claude.com/cookbook/multimodal-crop-tool).
10201020
10211021### Frontend design
10221022
1023Claude Opus 4.5 and Claude Opus 4.6 build complex, real-world web applications with strong frontend design. However, without guidance, models can default to generic patterns that create what users call the "AI slop" aesthetic. To create distinctive, creative front ends that surprise and delight:
1023Claude Opus 4.5 and Claude Opus 4.6 build complex, real-world web applications with strong frontend design. However, without guidance, models can default to generic patterns that create what users call the “AI slop” aesthetic. To create distinctive, creative front ends that surprise and delight:
10241024
10251025<Tip>
10261026 For a detailed guide on improving frontend design, see the blog post on [improving frontend design through skills](https://www.claude.com/blog/improving-frontend-design-through-skills).
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10281028
10291029For frontend design work outside the API, [Claude Design](https://support.claude.com/en/articles/14604416-get-started-with-claude-design) provides a canvas and design tools where Claude generates and iterates on designs interactively.
10301030
1031Here's a system prompt snippet you can use to encourage better frontend design:
1031Here’s a system prompt snippet you can use to encourage better frontend design:
10321032
10331033```text Sample prompt for frontend aesthetics wrap
10341034<frontend_aesthetics>
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10681068
10691069### Medication dosing
10701070
1071If people might ask your application about medicine doses, add the block below for the model your application calls to your system prompt, exactly as written. The block has Claude give a child's dose of an over-the-counter medicine from the product's label, not from memory. With web search, such as the [web search tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-search-tool), Claude checks the label before answering, which adds latency and search costs. Without web search, Claude points the person to the label's dosing chart, a pharmacist, or the child's doctor instead of giving a dose.
1071If people might ask your application about medicine doses, add the block below for the model your application calls to your system prompt, exactly as written. The block has Claude give a child’s dose of an over-the-counter medicine from the product’s label, not from memory. With web search, such as the [web search tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-search-tool), Claude checks the label before answering, which adds latency and search costs. Without web search, Claude points the person to the label’s dosing chart, a pharmacist, or the child’s doctor instead of giving a dose.
10721072
10731073```text Medication dosing block for Claude Sonnet 5.5 wrap
10741074<medical_guidance>
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11151115
11161116When migrating to current Claude models from earlier generations:
11171117
11181. **Be specific about the behavior you want:** Consider describing exactly what you'd like to see in the output.
11181. **Be specific about the behavior you want:** Consider describing exactly what you’d like to see in the output.
11191119
11202. **Frame your instructions with modifiers:** Adding modifiers that encourage Claude to increase the quality and detail of its output can help better shape Claude's performance. For example, instead of "Create an analytics dashboard," use "Create an analytics dashboard. Include as many relevant features and interactions as possible. Go beyond the basics to create a fully-featured implementation."
11202. **Frame your instructions with modifiers:** Adding modifiers that encourage Claude to increase the quality and detail of its output can help better shape Claude’s performance. For example, instead of “Create an analytics dashboard,” use “Create an analytics dashboard. Include as many relevant features and interactions as possible. Go beyond the basics to create a fully-featured implementation.”
11211121
112211223. **Request specific features explicitly:** Ask explicitly for animations and interactive elements when you want them.
11231123
No line in this hunk matches that.