You'll noticeTier: how much it should matter to you
1Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
SubagentsArea: what it touches
ImprovementsKind: in v2.1.307,
ImprovementsSection of the release
What
The description of the Agent tool was rewritten in the prompt Claude Code sends when a hook blocks a tool before it runs. A hook is a script you can configure to run at set points; a tool is an action Claude takes, such as reading a file. The Agent tool is how Claude passes work to a subagent, a separate helper copy of Claude.
The list of good reasons to delegate changed:
Removed: using the tool when the task matches an available agent type.
Added: using it when you ask for a side quest that shouldn't block the main thread of work.
Kept: independent work that can run in parallel, and answers that need reading across several files.
Why
This text is part of Claude's own instructions, so rewording it changes when Claude reaches for a helper. Side tasks you ask for are now named as a reason to delegate, while a matching agent type alone no longer is.
