Real tasks often need more than one tool. A support assistant may look up an order, check shipping status, inspect refund policy, and draft a response. A travel assistant may search flights, compare hotels, check weather, and convert prices. The engineering problem is coordinating several calls without losing control, not simply getting the model to call one function.

Multi-tool orchestration is the runtime pattern for that coordination. Some calls are independent and can run in parallel. Some are dependent and must run in sequence. Some should stop the workflow and ask the user for clarification. Some should be blocked by policy.

In this chapter, you will build orchestration loops that handle parallel calls, sequential chains, fallbacks, result aggregation, and stopping conditions.