Tool calling
Also: function calling
The model asking for a tool to be run, and the app running it and handing back the result.
The fuller definition
Tool calling is the process in which a model requests a named operation with arguments and the application executes it under its rules, then returns the result.
- Model request
Name and arguments
- Application
Authorize and execute
- Tool result
Return outcome
A simplified relationship, not a screenshot or a complete design.
A concrete example
The model requests search_documents with a query; the application performs the search.
The distinction that matters
A model-generated request is not proof that the operation actually ran or succeeded.
Related terms
Tool
Something an AI system can use to do a task. Examples include a search service, a calculator, and a file reader.
APIs & softwareAPI — Application Programming Interface
A doorway that lets one program talk to another. Apps use an API to send your request to the model and get the answer back.
Agents & automationAgent harness
The code that runs an agent's tools. It can keep logs and limit what the agent may do.
Where it is taught
Prompts, skills, workflows, and agentsSource and further reading
Anthropic · Building effective agentsThe definition and example are written for this library. The link gives background, official documentation or legal authority as labelled. Legal scope depends on the jurisdiction and current text; product features depend on release and settings.