Tools from the agent's point of view: how Claude Code designs tools

Seeing like an agent: how we design tools in Claude Code

The Claude Code team reviewed its tool design, stressing that tools keep changing with model capability, agent goals and runtime environment. AskUserQuestion became a standalone tool for structured questions after two failed attempts, and Task replaced TodoWrite with task dependencies and shared updates across subagents. Context retrieval moved from pre-indexed RAG to Grep search and progressive disclosure; the Claude Code Guide subagent searches docs in its own context and returns only the answer to the main agent.

Why it matters: The Claude Code team uses question asking, task collaboration and context search as examples of treating observed model behavior as the input to tool design.