Enforcing and Validating Structured Output
Understand how to enforce structured output in AI features by using forced tool calls and schemas. Learn to catch validation failures, implement retry strategies with limits, and know how to handle errors after retries. This lesson helps you ensure the AI output matches required formats, prevent malformed responses from disrupting applications, and integrate patterns used by real-world AI products.
The previous lesson made a contract more likely to be followed. More likely isn’t guaranteed. This lesson enforces the contract’s shape directly in code, so a malformed response never reaches the rest of the application, and then covers what to do on the rare response that still doesn’t hold up.
In this lesson, we will cover:
Why forcing a tool call is real enforcement, a structural constraint rather than a more polite request
What forced structured output does and doesn’t guarantee
How to catch a validation failure in code and retry with the model told exactly what went wrong
What to do after retries are exhausted
How the same pattern shows up in real products
The three ways engineers get this wrong
Structured output by a forced tool call
Every version of the support-summarizer’s code so far has used the same pattern. We define TicketSummary as a schema, wrap it in a tool definition, and pass tool_choice naming ...