Task/Agent tool's built-in instructions can now include a 'delegation costs first' framing, depending on the build
The Task tool (used to hand off work to a subagent, a separate Claude instance handling part of a task) now supports a delegationCostsFirst mode when its description is built. A new helper picks between two related settings depending on whether the client is a "compiled-only" build, choosing either delegationCostsFirstCompiledOnly or delegationCostsFirst.
A prompt capture taken under this release shows the Agent tool's stock description is 7,081 characters (its longest text across model variants), unchanged since the previous release.
This adds a way to have the tool's instructions emphasize the cost of delegating to a subagent before other considerations, though the description text itself has not changed yet in what's been captured.
What the delegationCostsFirst text actually says or when it's shown is not described beyond the setting names.