codeaashu-claude-code/docs/tools.md

Tools Reference

Complete catalog of all ~40 agent tools in Claude Code.

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Overview

Every tool lives in src/tools/<ToolName>/ as a self-contained module. Each tool defines:

• Input schema — Zod-validated parameters
• Permission model — What requires user approval
• Execution logic — The tool's implementation
• UI components — Terminal rendering for invocation and results
• Concurrency safety — Whether it can run in parallel

Tools are registered in src/tools.ts and invoked by the Query Engine during LLM tool-call loops.

Tool Definition Pattern

export const MyTool = buildTool({
  name: 'MyTool',
  aliases: ['my_tool'],
  description: 'What this tool does',
  inputSchema: z.object({
    param: z.string(),
  }),
  async call(args, context, canUseTool, parentMessage, onProgress) {
    // Execute and return { data: result, newMessages?: [...] }
  },
  async checkPermissions(input, context) { /* Permission checks */ },
  isConcurrencySafe(input) { /* Can run in parallel? */ },
  isReadOnly(input) { /* Non-destructive? */ },
  prompt(options) { /* System prompt injection */ },
  renderToolUseMessage(input, options) { /* UI for invocation */ },
  renderToolResultMessage(content, progressMessages, options) { /* UI for result */ },
})

Directory structure per tool:

src/tools/MyTool/
├── MyTool.ts        # Main implementation
├── UI.tsx           # Terminal rendering
├── prompt.ts        # System prompt contribution
└── utils.ts         # Tool-specific helpers

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File System Tools

Tool	Description	Read-Only
FileReadTool	Read file contents (text, images, PDFs, notebooks). Supports line ranges	Yes
FileWriteTool	Create or overwrite files	No
FileEditTool	Partial file modification via string replacement	No
GlobTool	Find files matching glob patterns (e.g. **/*.ts)	Yes
GrepTool	Content search using ripgrep (regex-capable)	Yes
NotebookEditTool	Edit Jupyter notebook cells	No
TodoWriteTool	Write to a structured todo/task file	No

Shell & Execution Tools

Tool	Description	Read-Only
BashTool	Execute shell commands in bash	No
PowerShellTool	Execute PowerShell commands (Windows)	No
REPLTool	Run code in a REPL session (Python, Node, etc.)	No

Agent & Orchestration Tools

Tool	Description	Read-Only
AgentTool	Spawn a sub-agent for complex tasks	No
SendMessageTool	Send messages between agents	No
TeamCreateTool	Create a team of parallel agents	No
TeamDeleteTool	Remove a team agent	No
EnterPlanModeTool	Switch to planning mode (no execution)	No
ExitPlanModeTool	Exit planning mode, resume execution	No
EnterWorktreeTool	Isolate work in a git worktree	No
ExitWorktreeTool	Exit worktree isolation	No
SleepTool	Pause execution (proactive mode)	Yes
SyntheticOutputTool	Generate structured output	Yes

Task Management Tools

Tool	Description	Read-Only
TaskCreateTool	Create a new background task	No
TaskUpdateTool	Update a task's status or details	No
TaskGetTool	Get details of a specific task	Yes
TaskListTool	List all tasks	Yes
TaskOutputTool	Get output from a completed task	Yes
TaskStopTool	Stop a running task	No

Web Tools

Tool	Description	Read-Only
WebFetchTool	Fetch content from a URL	Yes
WebSearchTool	Search the web	Yes

MCP (Model Context Protocol) Tools

Tool	Description	Read-Only
MCPTool	Invoke tools on connected MCP servers	Varies
ListMcpResourcesTool	List resources exposed by MCP servers	Yes
ReadMcpResourceTool	Read a specific MCP resource	Yes
McpAuthTool	Handle MCP server authentication	No
ToolSearchTool	Discover deferred/dynamic tools from MCP servers	Yes

Integration Tools

Tool	Description	Read-Only
LSPTool	Language Server Protocol operations (go-to-definition, find references, etc.)	Yes
SkillTool	Execute a registered skill	Varies

Scheduling & Triggers

Tool	Description	Read-Only
ScheduleCronTool	Create a scheduled cron trigger	No
RemoteTriggerTool	Fire a remote trigger	No

Utility Tools

Tool	Description	Read-Only
AskUserQuestionTool	Prompt the user for input during execution	Yes
BriefTool	Generate a brief/summary	Yes
ConfigTool	Read or modify Claude Code configuration	No

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Permission Model

Every tool invocation passes through the permission system (src/hooks/toolPermission/). Permission modes:

Mode	Behavior
default	Prompt the user for each potentially destructive operation
plan	Show the full plan, ask once
bypassPermissions	Auto-approve everything (dangerous)
auto	ML-based classifier decides

Permission rules use wildcard patterns:

Bash(git *)           # Allow all git commands
FileEdit(/src/*)      # Allow edits to anything in src/
FileRead(*)           # Allow reading any file

Each tool implements checkPermissions() returning { granted: boolean, reason?, prompt? }.

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Tool Presets

Tools are grouped into presets in src/tools.ts for different contexts (e.g. read-only tools for code review, full toolset for development).

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See Also

• Architecture — How tools fit into the overall pipeline
• Subsystems Guide — MCP, permissions, and other tool-related subsystems
• Exploration Guide — How to read tool source code