Dictionary term
Tool Calling
Also called Function Calling
A capability where the LLM outputs a structured request to invoke a defined function or tool, and your code runs it and returns the result for the model to use.
In plain English
The way an AI asks your software to do something real, like look up a contact or send a message, by filling in a structured request your code then runs.
Analogy
Like a chef calling out an order to a line cook: the chef decides what is needed, the cook does the actual work, and the result comes back.
Why it matters
It is how Claude actually performs real actions like sending a message or querying an API instead of just describing them.
In practice
The model returns a call to get_weather({"city":"Manila"}); your code runs it and feeds the temperature back.
Related terms
Sources
Browse all terms →Last verified