Under the hoodTier: how much it should matter to you
2Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
Agent ToolArea: what it touches
Internal ChangesKind: in v2.1.280,
Internal ChangesSection of the release
What
The system prompt's description of the Agent tool (used by the SDK and CLI to explain when Claude should delegate work to a subagent) was rewritten. Previously it gave a narrow rule mainly about not delegating simple single-fact lookups when the location was already known. The new version actively recommends delegating whenever a task matches an available agent type, involves independent parallel work, or spans several files.
Why
This pushes Claude to make more use of subagents for tasks that benefit from delegation, such as parallel or multi-file work, rather than doing everything inline in the main session.
