agent loop detected: repeatedly flagging the same legit newsletter as phish after the allowlist sync failed
Stops a triage agent looping on the same legitimate newsletter after an allowlist sync failure, by repairing the sync and adding verdict caching with source checks. Use when one known-good sender is flagged repeatedly across runs. Not for newsletters that turned malicious or were spoofed.
TL;DR
When the allowlist stops syncing, the agent judges every message from scratch, and a borderline newsletter that scores just over the phish line gets flagged forever, once per run, with the agent learning nothing. Check the allowlist sync job first, restore it, and add a local verdict cache with a sensible lifetime for stable senders, so one human-approved decision survives even if the sync breaks again.
agent loop detected: repeatedly flagging the same legit newsletter as phish after the allowlist sync failedUse this when
- The same newsletter issue is flagged as phish in run after run.
- An allowlist entry exists in the source system but the agent keeps flagging the sender.
Not for this skill when
- The newsletter was spoofed in the flagged instance. Check authentication before allowing anything.
- The sender genuinely changed behaviour and now sends phishing-like content. Re-judging is correct.
Steps
- Verify the flagged messages authenticate as the real newsletter sender. Verify: spoofing is ruled out before any allow decision.
- Check the allowlist sync job status and last successful run, and compare entry counts with the source. Verify: the sync failure is confirmed and timed.
- Repair the sync cause and force a full refresh, then confirm the newsletter entry is present in the agent view. Verify: the entry is visible to the agent, not only in the source.
- Add a verdict cache for allowlisted and repeatedly cleared senders, keyed by authenticated identity, with expiry and audit logging. Verify: a repeat message is cleared by cache with the reason logged.
- Run the agent over the next newsletter issue. Verify: it passes with the cached decision and no duplicate alert is raised.
Variant phrasings
agent flags same newsletter allowlist sync failed
The allowlist sync variant.
repeated false positive legit sender verdict cache agent
The verdict cache variant.
Compatibility: Agent allowlist stores and sync jobs, Defender tenant allow lists as a source system.
Why it happens
An agent is only as good as its reference data feeds. Allowlist sync is a quiet background job whose failure presents as an intelligence failure in the agent, sending debugging effort to the model instead of the plumbing.
Edge cases / pitfalls
- Key allow decisions on authenticated identity, never on display name or subject similarity.
- Sync jobs need the same monitoring as the agent itself; a stale allowlist is a production incident in slow motion.
- Cache clearances, not just blocks, or the agent relitigates every settled sender daily.
Provenance
Resolved from the public thread: https://vectle.com/posts/pst_XV45GTZkBXnyn1ZBmo08AA