# Claude Code v2.1.157: system prompt

> 1 of 27 tool descriptions changed. Compared against v2.1.156.

Web version: https://changelogs.core-directive.com/prompts/2.1.157?arm=sdk-cli

## What this version holds
- model strings captured: 27
- tool descriptions: 27
- compared against: v2.1.156
- system prompt edits: 0
- widest system prompt edit: +0/-0 lines
- tool descriptions changed: 1

## What moved

### Tool: EnterWorktree (+3/-1 lines)

This edit reached all 27 arms.

```diff
@@ from line 14 @@
 ## Requirements
 
 - Must be in a git repository, OR have WorktreeCreate/WorktreeRemove hooks configured in settings.json
-- Must not already be in a worktree
+- Must not already be in a worktree session when creating a new worktree (`name`); switching into another existing worktree via `path` is allowed
 
 ## Behavior
 
```

```diff
@@ from line 26 @@
 ## Entering an existing worktree
 
 Pass `path` instead of `name` to switch the session into a worktree that already exists (e.g., one you just created with `git worktree add`). The path must appear in `git worktree list` for the current repository — paths that are not registered worktrees of this repo are rejected. ExitWorktree will not remove a worktree entered this way; use `action: "keep"` to return to the original directory.
+
+Switching with `path` also works when the session is already in a worktree (the previous worktree is left on disk, untouched, and only the new one is tracked for exit-time cleanup), and from agents whose working directory was pinned at launch (subagent isolation or explicit cwd). In both cases the target must be a worktree under `.claude/worktrees/` of the same repository, and from a pinned agent the switch only affects this agent, not the parent session. After a further switch, previously-visited worktrees are no longer writable — re-issue EnterWorktree with `path` to return to one.
 
 ## Parameters
 
```

## Tool descriptions
- Agent: https://changelogs.core-directive.com/prompts/2.1.157/tools/Agent.txt?arm=sdk-cli
- AskUserQuestion: https://changelogs.core-directive.com/prompts/2.1.157/tools/AskUserQuestion.txt?arm=sdk-cli
- Bash: https://changelogs.core-directive.com/prompts/2.1.157/tools/Bash.txt?arm=sdk-cli
- CronCreate: https://changelogs.core-directive.com/prompts/2.1.157/tools/CronCreate.txt?arm=sdk-cli
- CronDelete: https://changelogs.core-directive.com/prompts/2.1.157/tools/CronDelete.txt?arm=sdk-cli
- CronList: https://changelogs.core-directive.com/prompts/2.1.157/tools/CronList.txt?arm=sdk-cli
- Edit: https://changelogs.core-directive.com/prompts/2.1.157/tools/Edit.txt?arm=sdk-cli
- EnterPlanMode: https://changelogs.core-directive.com/prompts/2.1.157/tools/EnterPlanMode.txt?arm=sdk-cli
- EnterWorktree (changed in this version): https://changelogs.core-directive.com/prompts/2.1.157/tools/EnterWorktree.txt?arm=sdk-cli
- ExitPlanMode: https://changelogs.core-directive.com/prompts/2.1.157/tools/ExitPlanMode.txt?arm=sdk-cli
- ExitWorktree: https://changelogs.core-directive.com/prompts/2.1.157/tools/ExitWorktree.txt?arm=sdk-cli
- Glob: https://changelogs.core-directive.com/prompts/2.1.157/tools/Glob.txt?arm=sdk-cli
- Grep: https://changelogs.core-directive.com/prompts/2.1.157/tools/Grep.txt?arm=sdk-cli
- NotebookEdit: https://changelogs.core-directive.com/prompts/2.1.157/tools/NotebookEdit.txt?arm=sdk-cli
- Read: https://changelogs.core-directive.com/prompts/2.1.157/tools/Read.txt?arm=sdk-cli
- ScheduleWakeup: https://changelogs.core-directive.com/prompts/2.1.157/tools/ScheduleWakeup.txt?arm=sdk-cli
- Skill: https://changelogs.core-directive.com/prompts/2.1.157/tools/Skill.txt?arm=sdk-cli
- TaskCreate: https://changelogs.core-directive.com/prompts/2.1.157/tools/TaskCreate.txt?arm=sdk-cli
- TaskGet: https://changelogs.core-directive.com/prompts/2.1.157/tools/TaskGet.txt?arm=sdk-cli
- TaskList: https://changelogs.core-directive.com/prompts/2.1.157/tools/TaskList.txt?arm=sdk-cli
- TaskOutput: https://changelogs.core-directive.com/prompts/2.1.157/tools/TaskOutput.txt?arm=sdk-cli
- TaskStop: https://changelogs.core-directive.com/prompts/2.1.157/tools/TaskStop.txt?arm=sdk-cli
- TaskUpdate: https://changelogs.core-directive.com/prompts/2.1.157/tools/TaskUpdate.txt?arm=sdk-cli
- WebFetch: https://changelogs.core-directive.com/prompts/2.1.157/tools/WebFetch.txt?arm=sdk-cli
- WebSearch: https://changelogs.core-directive.com/prompts/2.1.157/tools/WebSearch.txt?arm=sdk-cli
- Workflow: https://changelogs.core-directive.com/prompts/2.1.157/tools/Workflow.txt?arm=sdk-cli
- Write: https://changelogs.core-directive.com/prompts/2.1.157/tools/Write.txt?arm=sdk-cli

## Full text
- system prompt: https://changelogs.core-directive.com/prompts/2.1.157/system.txt?arm=sdk-cli