AI Digital Ideal

Oct 11, 2026 · Artificial Intelligence

Deep Dive into AI Agent Tool Use: From @tool Decorator Internals to Hand-Written Agent

This tutorial explains how AI agents use tools via Function Calling, demystifies the @tool decorator by showing how Python introspection generates OpenAI JSON schemas, provides a complete 60-line hand-written agent implementation, and outlines five golden rules for tool design including detailed docstrings, semantic parameter names, limiting tools to 20, single responsibility, and recoverable errors.