Tool call
Definition
A tool call is a single invocation of a tool by an AI agent - with concrete arguments and a result. Example: refund_order with amount=€180. Tool calls are where language becomes action: orders, refunds and deletions happen as tool calls, not as chat messages.
Controlling agents therefore means controlling tool calls: which agent invoked which tool, when, with which arguments, and what came back? Without that record, any statement about agent behavior is a guess.
In practice, tool calls carry per-tool rules - allow, require approval, or deny, refined with conditions such as amounts or business hours.
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