You'll notice
Notifications for stopped or failed background agents now split a short summary from a longer explanation
What
When a background agent (a task running outside your direct view), a background shell command, or a web-fetch launch stops or fails, the notification you get now carries two parts: a short summary line and a longer note (also called body) with the details. Individual agent notifications now start with a fixed line like Background agent "X", with the fuller explanation moved into the note.
Why
Separating a quick summary from the longer explanation makes it easier to scan notifications at a glance while still having the full detail available when you need it.