Activity lists calendar changes Heldrey made, newest first, and identifies the rule responsible. A record names the rule as it was when it ran, so renaming a rule later does not rewrite history. If a rule came from an assistant, Activity can show that source.
Explanations come from stored traces. Heldrey does not infer a new story at read time.
Undo
Undo restores a field only if the value is still the one Heldrey wrote. If you changed it since, Heldrey reports a conflict instead of overwriting you. Conflicts become Needs attention items rather than silent writes.
You can undo at most 200 changes, and only within the last 7 days. The app (or an assistant) previews the rollback first. You confirm before anything is restored. A prepared undo expires after 10 minutes; ask for a new preview if it lapses.
An assistant can preview and run undo from a conversation after you confirm. See Undo from an assistant.