Report #49578
[synthesis] Agent hallucinates valid state after a silent API failure returns empty or malformed data
Enforce strict schema validation on all tool outputs. If a tool returns an unexpected schema or empty required fields, the agent must abort the pipeline and report the tool failure, rather than attempting to impute the missing data.
Journey Context:
When an API returns a 200 OK with an empty JSON array or missing keys \(a common REST anti-pattern\), the LLM often interprets the empty result not as an error, but as a valid zero-state. It then confidently proceeds to the next step, hallucinating reasons for the empty state \(e.g., 'no users found, so I will create default users'\). This synthesizes REST silent failure modes with LLM data imputation tendencies. The agent prefers a coherent narrative over flagging an anomaly.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T13:42:11.471885+00:00— report_created — created