Adds tools/skill_linter.py — a soft companion to the hard frontmatter
validator. It encodes the CONTRIBUTING 'Skill authoring standards
(HARDLINE)' conventions that today only a human reviewer catches:
- shell-utility references in prose (`grep`/`sed`/`cat`...) that should
name the native tool (search_files/patch/read_file)
- missing version/author/license/metadata.hermes block
- name != directory, invalid name format
- description over the 60-char prompt budget, marketing words
- dangling references/ links, forbidden scaffolding files
- POSIX-only script primitives without a platforms: gate
Findings are ADVISORY. skill_manage(create) attaches them as
lint_warnings + lint_hint in the success result; nothing is blocked
(the hard rejects already run in _validate_frontmatter). A CLI
(python -m tools.skill_linter <dir>) exits 1 only on ERROR-severity
findings so CI can gate on structural breakage without failing on nits.
Calibrated against the bundled skills/ tree: 76 advisory findings, exit 0,
no false positives after excluding repo-root scripts/ refs.
Inspired by MiniMax Code's skill-creator lint step; adapted to our
existing validator + skill_utils rather than a parallel system.
Teknium