// AI
Tool Use
An LLM's ability to call external functions, APIs or MCP servers as part of its reasoning loop.
In depth
Tool use is what turns an LLM from a text generator into an agent. Modern agents chain dozens of tool calls per task: search CRM, enrich account, draft email, book meeting. Reliability of tool-use is the primary quality axis for enterprise agent platforms in 2026.
Related terms
Agent
An AI system that plans, uses tools and takes actions autonomously toward a goal, not just generates text.
Model Context Protocol
An open standard (introduced by Anthropic in late 2024) for connecting AI models to tools, data and services.
LLM
Large Language Model, the transformer-based foundation model behind ChatGPT, Claude, Gemini and every 2024+ AI product.