Analyzed: March 31, 2026 leak snapshot

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File-oriented tool set

The core file workflow is built from these primitives:
  • FileReadTool
  • FileEditTool
  • FileWriteTool
  • NotebookEditTool
  • GlobTool
  • GrepTool
  • TodoWriteTool
src/tools.ts keeps them in the default tool set, with GlobTool and GrepTool omitted only when the build exposes embedded search tools.

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Why there are multiple write tools

The source separates file mutation by intent:
  • FileEditTool: patch-style, targeted changes
  • FileWriteTool: full write or rewrite
  • NotebookEditTool: notebook-specific mutation path
That split is important for approvals and UI. The permission dialog can explain the action more precisely when the tool already encodes the editing style.

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Search versus read

Claude Code does not rely on FileReadTool for discovery. The intended read path is:
  1. discover candidate files with GlobTool or GrepTool
  2. read the relevant files with FileReadTool
  3. mutate with one of the write/edit tools
This keeps context narrower than reading everything up front.

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Approval profile

Tool familyTypical approval posture
Search (GlobTool, GrepTool)Usually auto-allowed
Read (FileReadTool)Usually auto-allowed inside workspace
Edit / writeFrequently approval-gated
Notebook editApproval-gated
The final decision still depends on permission mode, rules, hooks, and workspace restrictions.

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Workspace and trust implications

File tools are not just path-based wrappers. They run inside a larger policy model that includes:
  • workspace validation
  • additional working directory rules
  • path safety checks
  • policy and managed settings
  • sandbox mode where relevant
The permission system therefore decides on more than path in repo.

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Notebooks as a separate path

NotebookEditTool exists because notebooks need structure-aware edits rather than line-oriented patching. The public source confirms the tool is first-class, but implementation details beyond that are tool-local.

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Embedded search optimization

When embedded search tools are available in the Bun binary, GlobTool and GrepTool are removed from the exposed tool list. The comment in src/tools.ts states that Claude’s shell aliases can replace those dedicated tools in that build. That means search behavior can differ between builds even when the high-level user experience looks similar.

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Practical reading model

The file workflow is designed around three goals:
  • avoid loading irrelevant files into context
  • make writes explicit and auditable
  • keep search cheap compared with model context
That is a standard agentic editing design, but this codebase implements it as separate tools rather than a single overloaded filesystem API.