What is Tessary's malformed_output classifier?

malformed_output is a deterministic classifier: it checks whether an output matches the schema its call site declared, a pass or fail with no judgment involved. When a call site is set up to return structured data, Tessary captures that schema and validates every output against it, on every trace rather than a sample.

It catches exactly what your calling code would hit in production: output that doesn’t parse as valid JSON, or output that parses fine but violates the declared shape, a missing field, the wrong type, an extra wrapper around the object. Because the check is mechanical rather than judged, every firing is high confidence, and it carries the actual violation message as evidence.

Where a call site declares no schema, there’s nothing to check against, so the classifier stays quiet. A flag becomes a finding, not an alert, and triage decides whether it becomes a case.