The unquoted description contained "Costing methods: effort …" — the mid-string
": " made YAML treat it as a nested mapping ("mapping values are not allowed
here"), failing verify-skills since 2026-05-27. Single-quote the value (it has
inner double quotes but no apostrophes), preserving the exact text.
verify_skills.py: 76/76 skills valid.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>