Under the hood
Background-agent summaries now get rejected outright if unparseable, with a running count of failures
What
When Claude Code generates a short summary of what a background agent (a subagent running a task in the background) is doing, it now parses the model's reply and, if that parsing fails, throws the reply away instead of storing it as the summary. Previously it would just trim any non-empty reply and use it regardless. A count of consecutive rejected replies is now tracked and reported.
Why
This avoids showing garbled or unusable text as a background agent's summary, at the cost of sometimes having no summary at all when the model's reply can't be parsed.