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📚 Claude Tutorials Hub
40+ step-by-step Claude guides — prompt engineering, Claude Code, API, agents. Browse by topic →
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Industry news, technical articles, and product introductions
📚 Claude Tutorials Hub
40+ step-by-step Claude guides — prompt engineering, Claude Code, API, agents. Browse by topic →
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"Opus 5 verifies itself, so delete your fallback prompts" is advice you hear everywhere. I took it, then isolated both configs with CLAUDE_CONFIG_DIR and ran 18 headless trials on identical tasks. Output tokens dropped 21% and wall clock 20-29%, with zero counterexamples. But two of the rewritten rules never fired at all, and one result points the other way: the old config's most thorough run covered a strict superset of what the new one found. Why cheaper and better are separate questions.
'We removed over 80% of Claude Code's system prompt' — and the evals didn't move. The popular takeaway ('write shorter prompts') is wrong: what got deleted was constraints, not information. A usable dividing line, plus the API-layer mechanics the official post left out and the two real disagreements from 343 HN comments.