Group of 2 Under the hood
Spawned agents and subagents now carry an outputFileReadable flag based on which tools the session has available
What
Agent-spawn call sites now pass a new outputFileReadable field, computed from the session's available tool options, when creating a spawned agent or subagent task. A related caller also sets outputFileUnreadable: true when a corresponding flag is false. This is new state that did not exist before.
Why
This lets Claude Code know upfront whether a spawned agent's background output file can be read back later, rather than discovering it only when the read is attempted.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
The finding does not say what condition on session tools makes outputFileReadable true or false, or what breaks if it is set wrong.