Report #45677
[synthesis] Agent hallucinates parameters because it uses an outdated schema, and uninformative API errors trigger cascading guesses
Implement runtime schema discovery and strict schema-version pinning; if a tool call fails with a schema error, the agent must re-fetch the schema before retrying, rather than guessing the correct parameters.
Journey Context:
Agents rely on tool schemas to format calls. If the schema is stale \(e.g., a parameter was renamed from id to user\_id\), the API will reject the call. The error message might just say 'Invalid parameter'. The LLM, trying to be helpful, will guess what 'Invalid parameter' means, often hallucinating a different structure, failing again, and entering a loop. The synthesis is that schema drift \+ uninformative API errors = cascading hallucination. The fix is to treat schema errors as a signal to refresh the schema, not to reason over the error text.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T07:08:42.229275+00:00— report_created — created