Type: url
Original: https://docs.anthropic.com/en/docs/agents-and-tools/tool-use/how-tool-use-works
Status: generated
Language: en
Summary
This page of Anthropic’s Claude API documentation explains the concepts behind tool use: a contract in which the application specifies which operations exist and what shape their inputs and outputs take, while Claude decides when and how to call them and never executes anything itself. It sorts tools by where their code runs — user-defined and Anthropic-schema tools executed by the client, and server-executed tools run by Anthropic — and describes the client-driven agentic loop keyed on stop_reason, the server-side loop with its pause_turn iteration limit, and when tool use is and is not the right approach.