Checks that make the system usable

Test the actual caller

A tool working in an admin shell does not prove it works for its employee or agent identity.

Totals can hide stuck queues. Monitor unprocessed-item age, failed promotion and outcomes awaiting checks.

A successful backup job is not recovery. Restore in isolation and check records, permissions and behaviour.

A timeout may happen after a write was accepted. Read back by idempotency key first.

Enforce identity and scope in tools and source systems. Model instructions are not a security boundary.

Do not turn source failure into a polished old answer. Keep stale and conflicting states visible.

These are engineering methods, not public incident statistics.