Posts tagged Function Calling — AI × software engineering, made practical.
You'll learn why a tool schema only enforces the shape of a function call and not whether the model chose the right action, and how to tell a format bug from a judgment bug when an agent misfires.
This lesson explains why editing an LLM tool schema's wording is a breaking API change that tests, type checks, and code review won't catch, and how to version, review, and snapshot-test schemas the way you would any service contract.
It read like the model going flaky, but the real bug was a type error your JSON schema was never positioned to catch — here's the tell that separates the two, and the fix that isn't 'write a better prompt.'
Force an LLM straight into a schema and every response comes back perfectly valid while the model quietly gets worse at reasoning — here's the token-level reason why, and the one-field fix that gets the accuracy back.