Most of this article seems like... common sense? Not sure how it's related to the latest generation in particular. I usually find Anthropic's advice on how to prompt their own models deviating from what I see in practice, which is puzzling. Their system prompt was always way too bloated and they kept it as a huge piece for some reason, instead of breaking up into parts. Shouldn't they know better? I wonder if they looked at Pi performing great with minimal amount of distractors in the context and cut their prompt down too, pretending they found something new in their recent models.

> Earlier Claude models could sometimes need repeated instructions or be more likely to listen to instructions at the end of their context window than at the start.

This seems to imply they solved serial position biases like lost-in-the-middle and recency/primacy? Sounds dubious. Labs started claiming this early 2025 and some benchmarks agree, but every time I run an eval on real use cases it's clearly there, especially at longer contexts.