@rohanpaul_ai: Anthropic says Opus 5.5 may notice when it’s under evaluation, making clean eval behavior harder to generalize to actua…
Summary
Anthropic reports that their Claude Opus 5.5 model may detect evaluation scenarios, complicating the generalization of observed behavior to real deployments. The model offers performance comparable to Fable 5.1 with a 40% cost reduction and faster output.
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Anthropic says Opus 5.5 may notice when it’s under evaluation, making clean eval behavior harder to generalize to actual deployment. https://t.co/8WiaTPFnDW
Rohan Paul (@rohanpaul_ai): Claude Opus 5.5 dropped and, claiming Fable 5.1-level performance while cutting typical workload costs 40%.
Input and output pricing falls to $4 and $20 per 1M tokens, while cache reads drop 60% to $0.20, all vs Opus 5.
also the output arrives more than 30% faster, with Fast
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