Tool
Displays a tool call the agent makes, from input to output.
Default
States
Trace does not read tool parts. Map each part's state to a status and a title.
Output in a Sheet
For long output, wrap the Trace.Line in a Sheet.Trigger and show the output in the sheet.
Approval
A pending approval is a question for the person, not a step the agent took, so it sits outside Trace as an Item. Once the person answers, the tool goes back to being a line. See Confirmation.