Tool Calling in Spring AI 2.0: A Composable, Agentic Architecture

A technical deep-dive into Spring AI 2.0’s redesigned tool-calling system, which lifts the execution loop into the advisor chain as a composable, first-class component. Methods annotated with @Tool expose functionality with auto-generated JSON schemas, a recursive ToolCallingAdvisor manages the execution lifecycle, and a ToolSearchToolCallingAdvisor implements progressive tool disclosure via semantic search that reduces token cost by 34-64% when managing hundreds of tools. Spring AI 2.0 also supports consuming and exposing tools via the Model Context Protocol.