support.ts with this checkpoint. lookup_order reads a tiny in-memory catalog. In your application, its implementation would call your order service after checking the authenticated customer’s access.
Complete checkpoint
support.ts
Run it
Verify the result
The answer should report Friday for ORD-1042. The model chooses the tool; your function supplies the fact. The schema validates the shape of arguments. It does not establish ownership or eligibility. Keep those checks inside application code. Return a string or the SDK’sToolResult shape; serialize structured data when returning text.
Try a missing order: change the ID to ORD-9999. The assistant should report that the order was not found, rather than inventing a delivery date. A model can still produce an incorrect answer; this is a prompt to include in your evaluation set.
Remember the conversation
Continue to the next chapter.