blog-writing-tools
Anthropic Engineering — Writing Effective Tools for AI Agents
URL: https://www.anthropic.com/engineering/writing-tools-for-agents Publisher: Anthropic Engineering Retrieved: 2026-07-08
Summary
Anthropic Engineering post ("Writing effective tools for AI agents", aka "Writing tools for agents") on how to design tools/MCP servers that agents actually use well. Core themes: build a few thoughtful, consolidated tools targeting high-impact workflows rather than wrapping every API endpoint; namespace tools (by service/resource, prefix vs suffix) to clarify boundaries and save context; return high-signal context using semantic natural-language identifiers instead of opaque technical IDs (UUID/mime_type); optimize token efficiency via pagination/filtering/truncation, sensible default limits, response_format (concise vs detailed) enums, and actionable error messages; prompt-engineer tool descriptions as if onboarding a new hire; and drive improvement through an agentic evaluation loop (generate realistic eval tasks, run agentic while-loops, analyze transcripts/metrics, and let Claude Code improve the tools).