tool use
How an AI agent reaches outside itself: searching, calculating, or using other software.
On its own, a model can only write text. Tool use lets it ask for an action instead, such as a web search or a database lookup. The surrounding software runs the tool and hands the result back. The model then reads the result and decides its next step. Every tool is chosen and limited by the people who build the agent.
Think of it as
Like a manager who cannot leave the office but can phone the warehouse, the bank and the courier. They only reach what is on their phone list.
Example
A support agent is asked where an order is. It calls the shop's order-tracking tool with the order number. The tool answers "out for delivery", and the agent tells the customer.