What
A subagent is a helper agent Claude starts for a piece of work. It reports back through the SubagentHandback tool, and the result already said whether that hand-back was sent, flagged or withheld (handback).
- The Agent result now also carries
handbackReport, taken from the last hand-back's report. It is meant for a client to show instead ofcontentwhen a hand-back was sent or flagged. - Its
textis the subagent's whole report, never truncated. Anything in it that imitates Claude Code's own markup has backslashes inserted. - Its optional
warningholds auto mode's SECURITY WARNING, or a note that the review could not run. - When a hand-back recipient is worked out, the report now travels to that recipient along with the target.
- The description of
handbackwas rewritten.
Why
Apps built on Claude Code can show a subagent's full report as its own item, together with any security warning, instead of only as ordinary tool output.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
It is not clear whether the SubagentHandback tool is available to everyone or switched on only for some accounts.