# Tool Use History: From Yao 2022 ReAct to Anthropic MCP — 3-Year Birth of LLM Agents

> Source: https://sukruyusufkaya.com/en/learn/llm-muhendisligi/tool-use-tarihce-react-mcp
> Updated: 2026-05-13T13:00:31.795Z
> Category: LLM Mühendisliği
> Module: Module 20: AI Agents — Tool Use, Function Calling, MCP, Multi-Agent
**TLDR:** Historical and conceptual anatomy of LLM agents: Yao et al. 2022 ReAct paper ('Reasoning + Action' fusion), OpenAI function calling (June 2023, first standardization), Anthropic MCP (November 2024, open standard). Rise of LangChain, AutoGen, CrewAI frameworks. 'Why aren't LLMs sufficient alone, why do they need tools?' Practical face of AGI debate. Turkish agent use cases.