Tool-Calling Design Checklist

Get structured data you can trust

• Stop parsing the model's prose with string matching or a regexThe model rephrases and reformats across runs, so a prose parser breaks as soon as the wording shifts.
• Define the exact output shape as a schema and request itWithout a defined structure, the rest of your code cannot rely on the output like a typed function.
• Validate every response against the schema before using itConstrained output reduces malformed responses but does not eliminate them.
• On validation failure, retry the call or fall backPassing malformed data on lets one bad response corrupt everything downstream.