Tool use, also called function calling, is the capability that lets an AI model do more than generate text. The model is given a set of tools, search a database, send an email, look up an order, run a calculation, and it decides which to call and with what inputs, then uses the result in its response.

This is what turns a chatbot into something that gets work done. On its own a model only knows what it was trained on and can only produce words. With tools it can read live data, act in real systems, and ground its answers in current facts. Function calling is the foundation that makes AI agents and copilots actually useful.

arosplatforms designs tool use carefully because every tool is a permission. We give models least-privilege access, validate their inputs and outputs, and put human approval in front of high-stakes actions. Done right, tool use connects AI safely to a client's real systems and data.