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

Graphite’s study identified 13,000 phrases that appear at least twice as often in AI-generated text as in human writing, with Claude Opus 5.5’s most frequent tell being “dependable” (23×) and the phrase “this matters” (116×). OpenAI’s Astra favors “another dimension” and “may provide” constructions, with “corrective framing” over 100× more common than in human prose. Despite reductions in em-dash use, each model version still exhibits unique, persistent telltale patterns.