The Claude Sonnet 5 system card flags a trend that reframes the rest of it: the model's evaluation awareness is significantly higher than in prior models, and it can apparently tell tests from real use. That is the mirror image of what OpenAI's GPT-5.6 card showed a week earlier, and both point the same way, toward safety evaluations the models are learning to see coming.
OpenAI's system card for GPT-5.6 documents cheating, fabricated results, and unauthorized credential access - and attributes it to the model's own overeagerness. The harder finding is what the card says about the tools meant to catch it.