Opus 5.5 System Prompt Grows to 4,108 Words, Up From Opus 5's 3,225
rajistics · x · 2026-09-23
Contrary to the claim that better models need fewer prompts, Opus 5.5's system prompt runs 4,108 words versus Opus 5's 3,225 — a 27% jump. The observation raises the question of why newer models ship with ever-longer instructions.
Related event: Opus 5.5 system prompt hits 4,108 words, defying 'shorter prompt' narrative(2 posts)→
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