Tool calling
In OpenAI documentation, tool calling is another name for function calling: the model decides it needs an external tool and returns a tool call. In n8n, a tool is an additional resource the model can access for information or to take action in an external system.
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Source content checked . English translation published 2026-10-27.
In business automation
Tool calling is the mechanism by which a model requests an external capability. It lets the application return facts and actions from the system, provided that it validates each request and returns a reliable result.
Examples
These examples illustrate a possible workflow. Adapt the connections and rules to your own systems.
Business process example
A meeting assistant requests a tool to show available times. After the user selects a time, a separate request creates the meeting and returns an ID. Only then does the assistant confirm that the booking is complete.
Relevant tools
- OpenAI Agents SDK
- Tools connect model requests to executing code. The application controls execution and permissions.
What to check
- Do not say an action succeeded just because the model requested it. Wait for the tool result and handle failures too.