## TL;DR
Fix this in pre start task check agent by acting on the exact problem first: base every blocker claim on a task record retrieved for that hire, show the task owner and due date beside each blocker, recompute the open task count from the retrieved records, and drop any blocker that appears in no hire task record. Do not rerun the whole onboarding flow unchanged, because the same inputs produce the same failure. Prove the fix on one hire or one task first, then rerun the full scope and reconcile the results.

```text
agent hallucinating answers not in source data for check onboarding tasks before the start date error hallucination failure
```

## Use this when
- The operation in pre start task check agent fails with this exact problem: agent hallucinating answers not in source data for check onboarding tasks before the start date error hallucination failure.
- The same failure repeats on retry with unchanged inputs.
- A new hire start, an onboarding task, a first day step or a first week plan is blocked until this is resolved.

## Not for this skill when
- The notice is a platform outage from the vendor. Resolve that first, then return here if this problem remains.
- The operation completes and you only disagree with an HR policy call such as eligibility or a start date decision. That is a people team decision, not this failure.

## Steps
1. Reproduce the failure on one named hire or task in pre start task check agent and record the full problem text plus the hire, task or start date involved. Verify: the failure is reproduced on demand on a named scope, not only seen in a log.
2. Apply the specific fix for this problem: base every blocker claim on a task record retrieved for that hire, show the task owner and due date beside each blocker, recompute the open task count from the retrieved records, and drop any blocker that appears in no hire task record. Verify: the single failing hire or task now behaves as the fix predicts, or the corrected value is visible on the record.
3. Check neighbouring hires, tasks or start dates that share the same template, checklist or sync, because this class of failure rarely affects only one hire. Verify: the neighbouring items are listed and each is marked affected or clear.
4. Rerun the original operation in pre start task check agent on the previously failing scope, watching for the same problem rather than assuming success from a quiet log. Verify: the operation completes and the original problem does not appear.
5. Compare the result against the source of truth, the HRIS hire record, the signed offer or the current handbook page, so a silent partial success is caught. Verify: values match the source or every difference is named and explained.
6. Record the fix, the triggering input and the verification result on the onboarding log so the next occurrence is recognised immediately. Verify: the record names the problem, the fix applied and the evidence of success.

## Variant phrasings

### agent hallucinating answers not in source data for check onboarding tasks before the start date error hallucination failure
The verbatim form searchers paste from the console, report or run log. Treat it identically: same fix, same single hire proof, then the full rerun.

### How to fix - agent hallucinating answers not in source data for check onboarding tasks before the start date error hallucination failure
The how to phrasing for the same failure in pre start task check agent. The steps above apply unchanged; start at the reproduction step rather than skipping to the rerun.

### pre start task check agent troubleshooting for this failure
The symptom first phrasing used when the console hides the full problem. Surface the full problem first, confirm it matches the text block above, then follow the steps.

## Why it happens
Summarising from partial views lets an agent invent plausible blockers, wrong owners and wrong due dates, and record level recomputation is what separates real pre start risks from invented ones.

## Edge cases
- The hire record was edited, the start date moved or the manager changed after the failing run started. Refresh the hire state and reapply the fix against the current values, not the values from the failed run.
- The single hire proof passes but the full rerun still fails on other hires. Treat each remaining failure as its own scope, because a shared template or schedule can hide more than one cause.
- The source systems disagree on the correct value. The HRIS hire record governs who the hire is and when they start, the signed offer governs terms, and the current handbook governs policy wording; record which source won and why.

Compatibility: pre start task check agent at current versions, plus the HRIS, handbook or onboarding tool the query names; no extra tooling beyond access to the source records needed to verify results.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_qOp00jNqs-2m92c7iSjPdA