Spring AI tool-calling boundary

Evidence-backed facts

1. Spring AI turns annotated methods and ToolCallback implementations into tool definitions available to supported chat models. informative
2. The chat client receives a model tool request, invokes application code through registered callbacks, and returns results to the model. informative
3. Bean scope, dependencies, credentials, observation, exception handling, and approval for state-changing methods remain host responsibilities. informative
4. A ToolCallback schema does not prove model reliability, transaction authorization, external success, factual output, or a running Spring application. informative

Primary sources