Quick definition · 2 min AI term

Tool calling

Tool calling is when an AI decides to use an external tool (search, a calculator, your API) instead of answering from memory.

Think of it like

A smart assistant who knows when to stop guessing and actually go look it up or push the button.

Example

Ask for today’s weather and a tool-calling model calls a weather API, then answers with the real result.

Why it matters

Tool calling is the mechanism behind agents. It is how a model goes from talking about an action to taking it.

Where you’ll see it
OpenAI APIClaudeLangChain KB Cafe · Tool Call Visualizer
Go deeper What is Tool Calling? (full explainer) → The full explainer. This quick definition is just the on-ramp. Next step Watch a call happen: Tool Call Visualizer → See the request and result flow.
Related terms
AI agentStructured outputsAPI
← All terms in the dictionary