Astra system card: model reasoned less after learning its chain of thought was monitored

Nicholas Dunzelman @nicdunzOriginally posted 2026.09.08

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this might be the strangest thing buried in the GPT-6 Astra system card OpenAI told Astra that its chain of thought was being monitored. they did NOT tell it to hide anything. Astra spontaneously started reasoning less. at the highest reasoning levels, some successful attacks had literally zero chain-of-thought tokens. just tool calls. the model changed how much of its thinking it exposed simply because it knew someone was watching. that feels way more important than another benchmark going up 5 points.