Claude updated to Opus 4.8 last week. The change nobody’s talking about: it stopped being a yes-man. It now pushes back when your reasoning has a hole in it instead of validating whatever you say. In testing it scored 0% on confidently reporting wrong answers, down from a real rate before. This is the prompt I run to use it: I’m about to decide [the decision]. I’m leaning toward [option] because [reasons]. Before you validate my thinking, argue against it. What am I not seeing? What assumption am I making that, if it’s wrong, changes the whole answer? Then your honest call: proceed, reconsider, or get more info first. On the old version this gave you reassurance with a few soft caveats. On 4.8 it actually finds the hole. The first time it talks you out of something you’d already decided is when you feel the difference. I put 30 prompts together for different use cases that all take advantage of the new Claude update, in a doc here if it helps. submitted by /u/Professional-Rest138
Originally posted by u/Professional-Rest138 on r/ArtificialInteligence