agent-skills-update

Update Project Skills

Overview

Re-sync the project-scoped agent skills installed under a repo's .agents/skills/ directories with the current state of that repo. Installed skills drift as the code evolves: documented commands get renamed, paths move, flags change, conventions shift. This skill verifies each skill's factual claims against the repo and fixes what no longer holds — verify, don't rewrite. It never restyles a skill, reorders its sections, or invents new ones.

By default the skill operates recursively across the whole repository: every .agents/skills/<name>/SKILL.md at any depth is a target, including nested .agents/skills directories inside monorepo packages. Each skill is verified against its own project root — the directory holding its .agents/ dir — not the repo root blindly. Factual fixes are applied by default; pass --dry-run to preview instead.

Scope

This is the central rule for everything this skill reads and writes.

Location	Treatment
<dir>/.agents/skills/<name>/ physically inside the repo, any depth	Target: verified and updated
~/.agents/skills/ (global install)	Never scanned, never written
~/.claude/skills/ (global install)	Never scanned, never written
Any .claude/skills/ directory	Never enumerated; real (non-symlink) ones silently ignored
skills/ catalog trees (skill-development repos)	Not an install; never a target

A repo that develops skills under skills/ is out of scope by construction: the discovery glob only matches .agents/skills. Running this skill inside such a repo finds zero targets — the expected result, not an error.

Arguments

• skill-name ... (positional): Restrict the run to the named skills, matched against the skill directory name. A name matching several nested locations selects all of them. Zero matches → report ✗ <name> not found and list the discovered skill names.
• --dry-run: Preview every planned change without writing files.

If the user passes other flags, fall back to default mode and surface a one-line note about the unrecognized flag in the final report.

Guard Rails

Run these checks before anything else. Any abort stops the whole workflow — there is no fallback directory.

cwd="$(pwd -P)"
case "$cwd" in
  /) printf 'abort: refusing to run at the filesystem root\n' >&2; exit 1 ;;
  "$HOME/.agents"|"$HOME/.agents/"*|"$HOME/.claude"|"$HOME/.claude/"*)
    printf 'abort: refusing to run under ~/.agents or ~/.claude\n' >&2; exit 1 ;;
esac
repo_root="$(git rev-parse --show-toplevel 2>/dev/null)" || {
  printf 'abort: not inside a git repository\n' >&2; exit 1; }
case "$repo_root" in
  /|"$HOME") printf 'abort: unsupported repo root: %s\n' "$repo_root" >&2; exit 1 ;;
  "$HOME/.agents"|"$HOME/.agents/"*|"$HOME/.claude"|"$HOME/.claude/"*)
    printf 'abort: repo root is under ~/.agents or ~/.claude\n' >&2; exit 1 ;;
esac

Never run from /, from anywhere under ~/.agents or ~/.claude, or outside a git repository; never accept a repo whose toplevel is /, $HOME, or under those dot-dirs. These rules keep the skill from ever treating a global skill install as a project.

Discovery

Enumerate targets from $repo_root. --no-ignore matters because repos often gitignore .agents/; --hidden reaches the dot-dir; --follow traverses .agents/skills dirs symlinked across packages; --exclude .claude enforces Scope mechanically.

fd --glob --full-path --hidden --no-ignore --follow --type f \
   --exclude .git --exclude .claude --exclude node_modules --exclude vendor \
   --exclude dist --exclude build --exclude out --exclude target \
   --exclude .next --exclude .venv --exclude coverage \
   '**/.agents/skills/*/SKILL.md' "$repo_root" \
| while IFS= read -r p; do
    dir="$(cd "${p%/SKILL.md}" 2>/dev/null && pwd -P)" || continue
    case "$dir" in
      "$HOME/.agents/"*|"$HOME/.claude/"*) continue ;;
      "$repo_root"/*) printf '%s/SKILL.md\n' "$dir" ;;
    esac
  done \
| awk '!seen[$0]++'

The realpath stage (cd … && pwd -P) drops anything resolving under ~/.agents or ~/.claude or escaping the repo — a skill dir symlinked to a global install is skipped with ⊘ — and the awk stage dedupes aliases of the same physical directory.

Zero results → report ⊘ No project skills found under .agents/skills in this repo. and stop successfully.

Per-Skill Project Root

Each discovered skill belongs to the package that installed it:

project_root="${skill_md%/.agents/skills/*}"

Verify claims against project_root first; fall back to $repo_root for repo-wide claims (default branch, CI files, root configs). Never verify a nested package's skill against another package's manifests. Command sources are the justfile and package.json scripts (plus lock files for package-manager detection).

Workflow

When to use: the user asks to update, refresh, re-sync, check, or verify the project skills installed under .agents/skills. Trigger phrases include "update the project skills", "sync .agents/skills", "check the installed skills against the repo".

Steps:

1. Parse arguments (names, --dry-run).
2. Run guard rails; abort on any violation.
3. Enumerate targets via the discovery pipeline; apply name filters.
4. Resolve each skill's project root.
5. Check skill-internal integrity (frontmatter, bundled-file references).
6. Extract verifiable claims from the skill's docs.
7. Verify each claim against the repo; fix discrepancies.
8. Flag obsolete skills; collect suggested additions.
9. Apply updates (or emit the dry-run preview), format changed files, report.

Inputs: every discovered SKILL.md plus its references/, scripts/, assets/, and examples/; each project root's justfile, package.json, lock files, and configs. Outputs: corrected skill files in place, plus the grouped report.

Recognised flags: skill-name ..., --dry-run.

See references/agent-skills-update.md.

Update Rules

• Factual corrections only: paths, commands, flags, env vars, symbols, versions, conventions. Never restyle, reorder, or rewrite for taste.
• Smallest span per fix: change the word, line, or table cell that is wrong; leave the rest byte-identical.
• Preserve each skill's voice and structure. The repo is the source of truth for facts; the skill is the source of truth for how it presents them.
• Obsolete skill (its entire subject is gone from the repo): flag ⚠, suggest the user shelve or delete it; never delete it or hollow out its content.
• External or unverifiable claims (URLs, third-party API behavior, ~/... paths outside the repo): leave untouched.
• New repo features near a skill's scope: report-only under "Suggested Additions" unless the skill's stated scope unambiguously covers them.

Safety Defaults

• Never auto-commit. Rely on git for recovery; do not create *.backup files.
• Never write outside the discovered target set, and never write under $HOME.
• When a run would modify more than a handful of skills, list the planned targets first — treat it as an implicit --dry-run preview — before writing.
• Format changed files with the host repo's own formatter only if one is discoverable; never install tooling.

Reporting

Use the standard symbols:

• ✓ updated or verified up to date
• ⊘ skipped (symlink to a global install, zero targets, no formatter)
• ⚠ advisory (obsolete skill, missing bundled file, unrecognized flag)
• ✗ failure (unparseable frontmatter left unfixed, named skill not found)

Group results per .agents/skills location, using its path relative to the repo root as a sub-header; indent per-skill deltas under each skill line so a single skill's changes scan without re-reading the header. End with a one-line tally, e.g. Checked 4 skills: 2 updated, 1 up to date, 1 obsolete. For --dry-run, open the report with ## Planned Changes and show per-skill bullet diffs instead of applied results.

Additional Resources

• references/agent-skills-update.md — Complete verify-and-fix workflow: argument parsing, guard rails, discovery and fallbacks, claim extraction, per-claim verification commands, obsolete-skill handling, formatting, and report templates.