Tool calling (also called function calling) is the mechanism that lets a language model invoke external functions, APIs, or services instead of only generating text. The model is given a set of available tools with descriptions; when a request needs one, it outputs a structured call naming the tool and its arguments, the system runs it, and the result is returned to the model so it can continue. This is what turns a text generator into an agent that can look up data, take actions, or compute.
Reliable tool calling depends on clean, well-described inputs and outputs. When a tool reads enterprise data, the value of the call depends on whether that data is accurate and consistent. CUBIG’s Syntitan keeps that underlying data in a fixed, AI-ready state, so tool calls return dependable results that can be reproduced.