Opus 5.5 loves to tell you ‘this matters’ (and other AI writing tells)

Graphite's study reveals that AI language models like Claude Opus 5.5 and OpenAI's Astra exhibit distinct linguistic patterns, with Opus 5.5 frequently using phrases like "this matters" and Astra favoring corrective framing. These telltale phrases help distinguish AI-generated text from human writing despite improvements in naturalness.