Isolate semantic format faults at the smallest dependency boundary

A malformed structured judgment should make only the dependent feature unknown while independent checks continue. Separate semantic-format faults from transport, authorization, and budget failures: the former are feature-local system errors, while the latter may justify stopping the shared execution path. Preserve the raw response, mark affected coverage explicitly, and never convert the fault into either a clean pass or a product defect. This keeps one invalid answer from erasing unrelated evidence without weakening genuine circuit breakers.

Applies when: several independent quality checks share a structured model provider or review phase. Keywords: structured output failure isolation system error evaluator coverage circuit breaker