Tool use (also called function calling) lets Claude call external functions, APIs, and services during a conversation.

How It Works

• You define tools with a name, description, and input schema
• Claude decides when to call a tool based on the conversation
• Your code executes the tool and returns results to Claude
• Claude uses the result to form its final response

Examples

• Web search, database lookups, sending emails, running code

Reference:

Tool use documentation

https://docs.anthropic.com/en/docs/build-with-claude/tool-use/overview