Techniques
Tool Use (Function Calling)
Also known as: function calling, tools
In one line
Letting an AI trigger external tools or APIs — like calling a function in code.
What does Tool Use (Function Calling) mean?
Tool use lets an LLM decide to invoke a defined function (send an email, look up a price, run SQL) and then use the result to continue reasoning. It's the foundation of agents.
A real-world example
Claude deciding to call your `get_order_status(order_id)` function when a customer asks "where's my order?".