Tool Use And Schema Validation

Agent provides three tools and sets tool_choice=auto. The user query 'what time is it in Tokyo?' clearly needs the get_time tool.

Pass tool_choice={type:'auto'} (or omit; auto is default when tools are present). Allow the model to decide whether to call. Do not pre-route by string-matching the user query and forcing a tool — that bypasses model reasoning.

Workflow requires the next assistant message to call the submit_invoice tool — no other tool and no plain-text response.

Set tool_choice={type:'tool', name:'submit_invoice'}. The next assistant response will contain a tool_use block for submit_invoice and no text block. Handle the resulting tool_use_id and pair with tool_result.

Model returns two tool_use blocks in one assistant turn: get_weather(SF) and get_weather(NYC). Agent dispatches both in parallel.

On the next user turn, include two tool_result blocks — one per tool_use_id, matched exactly by tool_use_id. Order of tool_results within the user turn is independent of dispatch order; matching is by id.