AI Tool Use 2026
What is Tool Use? LLM calls external functions to extend capabilities. How It Works 1. Define functions 2. LLM decides when to call 3. Execute function 4. Return result to LLM 5. LLM continues Examples - Search the web - Run code - Query database - Send email - Read file Frameworks - LangChain - LlamaIndex - OpenAI Functions - Anthropic Tool Use - Custom Patterns - Sequential - Parallel - Conditi…