Tool System Overview

Applies to: 4.0.8.1+

This section is organized into 5 practical tracks:

1. How to use tools: register tools, let model decide calls, inspect runtime effects
2. Built-in tools: one page per common BuiltInTool
3. Runtime process: end-to-end Tool Loop behavior in request lifecycle
4. Handlers: default behavior and replacement points
5. Additional notes: safety, observability, concurrency, tests, migration

1) Reading Map

Topic	Page
Tool usage + runtime effect	Tool Quickstart
Full runtime process	Tool Runtime (Tool Loop)
Default handlers and customization	Tool Handlers (Default & Replace)
Additional engineering notes	Tool Notes & Best Practices

2) Built-in Tools (one page each)

• Search Tool
• Browse Tool
• Cmd Tool
• Playwright Tool
• PyAutoGUI Tool
• MCP Integration

3) Tool System Map

4) Suggested Order

1. Start with Tool Quickstart
2. Read Tool Runtime (Tool Loop)
3. Then Tool Handlers (Default & Replace)
4. Use specific built-in pages by scenario