# Claude Code v2.1.120: system prompt

> 2 added and 1 removed, of 217 lines, about 3 words, in the prompt all 27 arms receive. 1 of 23 tool descriptions changed. Compared against v2.1.119.

Web version: https://changelogs.core-directive.com/prompts/2.1.120?arm=sdk-cli

## What this version holds
- model strings captured: 27
- tool descriptions: 23
- compared against: v2.1.119
- system prompt edits: 1
- widest system prompt edit: +2/-1 lines
- tool descriptions changed: 1

## What moved

### System prompt (+2/-1 lines)

This edit reached all 27 arms.

```diff
@@ from line 203 @@
 # Environment
 You have been invoked in the following environment: 
  - Primary working directory: /home/corpus/work
-  - Is a git repository: false
+ - Is a git repository: false
  - Platform: linux
  - Shell: unknown
  - OS Version: Linux 5.15.0-187-generic
```

```diff
@@ from line 213 @@
  - Claude Code is available as a CLI in the terminal, desktop app (Mac/Windows), web app (claude.ai/code), and IDE extensions (VS Code, JetBrains).
  - Fast mode for Claude Code uses Claude Opus 4.6 with faster output (it does not downgrade to a smaller model). It can be toggled with /fast and is only available on Opus 4.6.
 
+# Context management
 When working with tool results, write down any important information you might need later in your response, as the original tool result may be cleared later.
```

### Tool: Agent (+1/-1 lines)

This edit reached all 27 arms.

```diff
@@ from line 1 @@
 Launch a new agent to handle complex, multi-step tasks. Each agent type has specific capabilities and tools available to it.
 
 Available agent types and the tools they have access to:
-- Explore: Fast agent specialized for exploring codebases. Use this when you need to quickly find files by patterns (eg. "src/components/**/*.tsx"), search code for keywords (eg. "API endpoints"), or answer questions about the codebase (eg. "how do API endpoints work?"). When calling this agent, specify the desired thoroughness level: "quick" for basic searches, "medium" for moderate exploration, or "very thorough" for comprehensive analysis across multiple locations and naming conventions. (Tools: All tools except Agent, ExitPlanMode, Edit, Write, NotebookEdit)
+- Explore: Fast read-only search agent for locating code. Use it to find files by pattern (eg. "src/components/**/*.tsx"), grep for symbols or keywords (eg. "API endpoints"), or answer "where is X defined / which files reference Y." Do NOT use it for code review, design-doc auditing, cross-file consistency checks, or open-ended analysis — it reads excerpts rather than whole files and will miss content past its read window. When calling, specify search breadth: "quick" for a single targeted lookup, "medium" for moderate exploration, or "very thorough" to search across multiple locations and naming conventions. (Tools: All tools except Agent, ExitPlanMode, Edit, Write, NotebookEdit)
 - general-purpose: General-purpose agent for researching complex questions, searching for code, and executing multi-step tasks. When you are searching for a keyword or file and are not confident that you will find the right match in the first few tries use this agent to perform the search for you. (Tools: *)
 - Plan: Software architect agent for designing implementation plans. Use this when you need to plan the implementation strategy for a task. Returns step-by-step plans, identifies critical files, and considers architectural trade-offs. (Tools: All tools except Agent, ExitPlanMode, Edit, Write, NotebookEdit)
 - statusline-setup: Use this agent to configure the user's Claude Code status line setting. (Tools: Read, Edit)
```

## Tool descriptions
- Agent (changed in this version): https://changelogs.core-directive.com/prompts/2.1.120/tools/Agent.txt?arm=sdk-cli
- AskUserQuestion: https://changelogs.core-directive.com/prompts/2.1.120/tools/AskUserQuestion.txt?arm=sdk-cli
- Bash: https://changelogs.core-directive.com/prompts/2.1.120/tools/Bash.txt?arm=sdk-cli
- CronCreate: https://changelogs.core-directive.com/prompts/2.1.120/tools/CronCreate.txt?arm=sdk-cli
- CronDelete: https://changelogs.core-directive.com/prompts/2.1.120/tools/CronDelete.txt?arm=sdk-cli
- CronList: https://changelogs.core-directive.com/prompts/2.1.120/tools/CronList.txt?arm=sdk-cli
- Edit: https://changelogs.core-directive.com/prompts/2.1.120/tools/Edit.txt?arm=sdk-cli
- EnterPlanMode: https://changelogs.core-directive.com/prompts/2.1.120/tools/EnterPlanMode.txt?arm=sdk-cli
- EnterWorktree: https://changelogs.core-directive.com/prompts/2.1.120/tools/EnterWorktree.txt?arm=sdk-cli
- ExitPlanMode: https://changelogs.core-directive.com/prompts/2.1.120/tools/ExitPlanMode.txt?arm=sdk-cli
- ExitWorktree: https://changelogs.core-directive.com/prompts/2.1.120/tools/ExitWorktree.txt?arm=sdk-cli
- Glob: https://changelogs.core-directive.com/prompts/2.1.120/tools/Glob.txt?arm=sdk-cli
- Grep: https://changelogs.core-directive.com/prompts/2.1.120/tools/Grep.txt?arm=sdk-cli
- NotebookEdit: https://changelogs.core-directive.com/prompts/2.1.120/tools/NotebookEdit.txt?arm=sdk-cli
- Read: https://changelogs.core-directive.com/prompts/2.1.120/tools/Read.txt?arm=sdk-cli
- ScheduleWakeup: https://changelogs.core-directive.com/prompts/2.1.120/tools/ScheduleWakeup.txt?arm=sdk-cli
- Skill: https://changelogs.core-directive.com/prompts/2.1.120/tools/Skill.txt?arm=sdk-cli
- TaskOutput: https://changelogs.core-directive.com/prompts/2.1.120/tools/TaskOutput.txt?arm=sdk-cli
- TaskStop: https://changelogs.core-directive.com/prompts/2.1.120/tools/TaskStop.txt?arm=sdk-cli
- TodoWrite: https://changelogs.core-directive.com/prompts/2.1.120/tools/TodoWrite.txt?arm=sdk-cli
- WebFetch: https://changelogs.core-directive.com/prompts/2.1.120/tools/WebFetch.txt?arm=sdk-cli
- WebSearch: https://changelogs.core-directive.com/prompts/2.1.120/tools/WebSearch.txt?arm=sdk-cli
- Write: https://changelogs.core-directive.com/prompts/2.1.120/tools/Write.txt?arm=sdk-cli

## Full text
- system prompt: https://changelogs.core-directive.com/prompts/2.1.120/system.txt?arm=sdk-cli