Phase 1 (add the destination label) succeeded.
Failure detail when added or removed is false; null otherwise.
Apollo id of the account or contact.
true — the verify re-read still found the source label attached (quirk #2). false — the verify re-read confirmed it is gone. null — no verify pass ran, or the re-read itself failed; state unknown.
Phase 2 (remove the source label) succeeded.
One record's move outcome.
added/removedtrack the two PATCH phases separately, because an add that succeeded followed by a remove that failed leaves the record in both lists — a state the caller has to be able to see.