Basically all our code gets written by agents now, and so do the tests. Usually same session, same model. And I keep hitting the same loop:
Agent builds the feature
Agent writes the tests, everything green
Ship it
A user hits an edge, I dig in, and the tests were checking what the code does, not what the ticket asked for. Suite was green the whole time.
The annoying part is that if the model misread the ticket, its tests misread it the same way. It's basically marking its own homework. The model is just agreeing with itself.