DEFINITION
Tool Calling
Tool Calling / Function Calling
Definition
The ability of an LLM to invoke external functions or APIs during a conversation. The model outputs a structured call (name + arguments), the host executes it, and returns the result to the model. This is what makes agents actually *do* things rather than just talk.
Examples in the Wild
- Example 1:Model calls `search_web(query='ETH price')` and gets live data back
- Example 2:Model calls `send_email(to='...', subject='...', body='...')` to send an actual email