Id of the call that failed, matching the ToolCallStartedPayload that announced it.
How long the call ran before failing, in milliseconds.
OptionalerrorWhat went wrong, in one line, when the server said.
Taken from the failure the server reports in extra
(extra.error.message), and from output when that is
a plain string instead. Absent when the server sent neither, which is why an application
that shows the reason needs a fallback of its own; the full structured failure — its kind,
code and any data — is in extra.error.
Any additional metadata the server reported with the failure.
The arguments the call was made with.
Name of the tool that was called.
Whatever the failed call produced, if anything.
Any JSON value — the server's own type for a tool result is unconstrained, and on a failure it is commonly the reason as a plain string rather than a structured result. Narrow it before use. The string case is also given to you as error, which is what to show.
When the call failed, as reported by the server.
The payload of a ToolCallEvent.Error event: a tool call failed.
Delivered to onToolEvent — see ToolEventCallback. Read error for what went wrong. The agent carries on with the conversation; the SDK does not retry.