One change
Extend Claude Code
features-overview
Nearest release: v2.1.234, published 4 hours before this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
features-overview Changed · +13 / -11 lines
from line 209
Each feature has a different loading strategy and context cost: -| Feature | When it loads | What loads | Context cost | -| --------------------- | ------------------------------ | --------------------------------------------------- | -------------------------------------------- | -| **CLAUDE.md** | Session start | Full content | Every request | -| **Skills** | Session start + when used | Descriptions at start, full content when used | Low (descriptions every request)\* | -| **MCP servers** | Session start | Tool names; full schemas on demand | Low until a tool is used | -| **Code intelligence** | After file edits and on demand | Diagnostics after edits; symbol locations on lookup | Low; reduces file reads elsewhere | -| **Subagents** | When spawned | Fresh context with specified skills | Isolated from main session | -| **Hooks** | On trigger | Nothing (runs externally) | Zero, unless hook returns additional context | +| Feature | When it loads | What loads | Context cost | +| --------------------- | ------------------------------ | -------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------- | +| **CLAUDE.md** | Session start | Full content | Every request | +| **Skills** | Session start + when used | Descriptions at start, full content when used | Low (descriptions every request)\* | +| **MCP servers** | Session start | Tool names; full schemas on demand | Low until a tool is used | +| **Code intelligence** | After file edits and on demand | Diagnostics after edits; symbol locations on lookup | Low; reduces file reads elsewhere | +| **Subagents** | When spawned | Fresh context with specified skills, or the parent conversation for a [fork](/docs/en/sub-agents#fork-the-current-conversation) | Isolated from main session | +| **Hooks** | On trigger | Nothing (runs externally) | Zero, unless hook returns additional context | -\*By default, skill descriptions load at session start so Claude can decide when to use them. Set `disable-model-invocation: true` in a skill's frontmatter to hide it from Claude entirely until you invoke it manually. This reduces context cost to zero for skills you only trigger yourself. For a skill you didn't write, set [`skillOverrides`](/docs/en/skills#override-skill-visibility-from-settings) in settings to do the same without editing its file. +\*By default, skill descriptions load at session start so Claude can decide when to use them. Set `disable-model-invocation: true` in a skill's frontmatter to hide it from Claude entirely until you invoke it manually. For a skill you didn't write, set [`skillOverrides`](/docs/en/skills#override-skill-visibility-from-settings) in settings to do the same without editing its file. ### Understand how features load
from line 285
* CLAUDE.md and git status, except the built-in Explore and Plan agents [omit both](/docs/en/sub-agents#what-loads-at-startup) * Whatever context the lead agent passes in the prompt - **Context cost:** Isolated from main session. Subagents don't inherit your conversation history or invoked skills. + For a [fork](/docs/en/sub-agents#fork-the-current-conversation), Claude Code loads the parent's conversation so far, system prompt, and tools instead. + + **Context cost:** Isolated from main session. <Tip>Use subagents for work that doesn't need your full conversation context. Their isolation prevents bloating your main session.</Tip> </Tab>