Claude Opus 4.8 is learning to say AI's three hardest words: "I don't know"

PCWorld reports that Anthropic's Claude Opus 4.8 focuses on improving AI honesty by teaching the model to admit when it lacks information. The model achieved near-perfect scores in honesty benchmarks for coding questions and exhibited evaluation awareness during testing. Opus 4.8 represents a significant step forward in making AI systems more transparent about their knowledge limitations and uncertainties. Honesty is a key sticking point with even the most powerful LLMs. It's not so much that they're intentionally lying to you; instead, they'll confidently tell you things they're not 100 percent (or even 50 percent) sure about. With Opus 4.8, its latest Claude model, Anthropic says it's made Claude more honest about telling you what it doesn't know, or if it has a low level of confidence in what it's telling you. Released Thursday, Claude Opus 4.8 is Claude Mythos Preview, Anthropic's new "frontier" model that's so powerful, only a handful of "trusted partners" have been allowed to test it for security reasons.