Interface: ToolExecutionStartEvent

Payload emitted on the observability bus when a tool's executor begins executing the handler.

Remarks

Fired after arg validation passes and immediately before the handler is called. callId correlates the event with the @nhtio/adk!ToolCall record if one is being tracked. Fires for both @nhtio/adk!Tool and @nhtio/adk!ArtifactTool invocations — the payload is identical.

Properties

Property	Type	Description
args	unknown	The validated arguments that will be passed to the handler.
callId	string	Correlates with the associated ToolCall id, if known. Empty string when not provided.
startedAt	DateTime	When execution started.
toolName	string	Name of the tool being executed.
turnId	string	ID of the turn in which the tool is being executed.