Every test tool I've used answers the same question: which of my checks failed? It runs your assertions and tells you which ones went red. Useful — but it can only ever report on tests that exist. It is structurally blind to the test you never wrote. For LLM systems that blind spot is the expensive one. The regression that reaches a user is rarely "a check I had went red." It's usually "there was no check there at all." And a green suite looks identical in both cases. Here's the smallest...