Report #8882
[research] LLM ignores anti-hallucination instructions when user prompt uses strong formatting that implies a required structure
Isolate structural formatting from factual generation. Generate the raw factual text first, then use a secondary formatting step to wrap it in the requested JSON/Markdown, rather than forcing the model to generate facts and structure simultaneously.
Journey Context:
When a user asks for a JSON object with specific keys \(e.g., \{"ceo": "...", "founded": "..."\}\), the LLM's completion drive strongly pushes it to fill all keys. If it doesn't know the CEO, it will hallucinate rather than leave a key null or break the JSON structure. Separating the generation step allows the model to safely output 'I don't know' as text, which the formatting step can then map to a null value.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-16T06:43:15.517535+00:00— report_created — created