Design Reliable LLM Tool Calls with Structured Outputs
Giving a language model access to tools changes what an AI application can do. Instead of only producing text, the model can request a database lookup, search a document index, calculate a value, or trigger an application operation. The difficult part is not exposing a function. It is deciding which responsibilities belong to the model and which must remain under application control. A useful mental model is: model proposes an action application validates the proposal application decides whether to execute it tool returns data model explains or uses the result This separation makes tool-calling systems easier to reason about. The model handles interpretation and selection. Deterministic application code handles authorization, validation, execution, and state changes.