---

name: create-skill locale: caveman-ultra source_locale: en source_commit: 82c77053 fence_basis_commit: 82c77053 translator: "Julius Brussee homage — caveman" translation_date: "2026-04-19" description: > Create a new SKILL.md file following the Agent Skills open standard (agentskills.io). Covers frontmatter schema, section structure, writing effective procedures with Expected/On failure pairs, validation checklists, cross-referencing, and registry integration. Use when codifying a repeatable procedure for agents, adding a new capability to the skills library, converting a guide or runbook into agent-consumable format, or standardizing a workflow across projects or teams. license: MIT allowed-tools: Read Write Edit Bash Grep Glob metadata: author: Philipp Thoss version: "1.2" domain: general complexity: intermediate language: multi tags: meta, skill, agentskills, standard, authoring

Create a New Skill

Author SKILL.md → agents execute procedure.

Use When

• Codify repeatable proc for agents
• New cap → skills lib
• Guide/runbook → agent-consumable
• Std workflow across projects/teams

In

• Required: Task
• Required: Domain — 1 of 48 in skills/_registry.yml: r-packages, jigsawr, containerization, reporting, compliance, mcp-integration, web-dev, git, general, citations, data-serialization, review, bushcraft, esoteric, design, defensive, project-management, devops, observability, mlops, workflow-visualization, swarm, morphic, alchemy, tcg, intellectual-property, gardening, shiny, animal-training, mycology, prospecting, crafting, library-science, travel, relocation, a2a-protocol, geometry, number-theory, stochastic-processes, theoretical-science, diffusion, hildegard, maintenance, blender, visualization, 3d-printing, lapidary, versioning
• Required: Complexity (basic/intermediate/advanced)
• Optional: Src (guide/runbook/working example)
• Optional: Related skills

Do

Step 1: Create Dir

Each skill → own dir:

mkdir -p skills/<skill-name>/

Naming:

• Kebab-case lowercase: submit-to-cran, not SubmitToCRAN
• Start w/ verb: create-, setup-, write-, deploy-, configure-
• Specific: create-r-dockerfile not create-dockerfile

Got: Dir exists, name = kebab-case + verb.

If err: No verb → rename. Check conflicts: ls skills/ | grep <keyword>.

Step 2: YAML Frontmatter

---
name: skill-name-here
description: >
  One to three sentences plus key activation triggers. Must be clear
  enough for an agent to decide whether to activate this skill from
  the description alone. Max 1024 characters. Start with a verb.
license: MIT
allowed-tools: Read Write Edit Bash Grep Glob  # optional, experimental
metadata:
  author: Philipp Thoss
  version: "1.0"
  domain: general
  complexity: intermediate
  language: R | TypeScript | Python | Docker | Rust | multi
  tags: comma, separated, lowercase, tags
---

Required: name, description

Optional: license, allowed-tools (experimental), metadata, compatibility

Metadata:

• complexity: basic (<5 steps), intermediate (5-10), advanced (10+)
• language: primary; multi for cross-lang
• tags: 3-6, include domain

Got: YAML parses, name = dir, description <1024 chars + triggers.

If err: Validate — --- matched, "1.0" (not 1.0), > multi-line fold for desc.

Step 3: Title + Intro

# Skill Title (Imperative Verb Form)

One paragraph: what this skill accomplishes and the value it provides.

Title = name in readable. "Submit to CRAN" not "submit-to-cran".

Got: # heading imperative + concise para.

If err: Noun phrase → rewrite verb. "Package Submission" → "Submit to CRAN."

Step 4: When to Use

3-5 triggers — concrete scenarios:

## When to Use

- Starting a new R package from scratch
- Converting loose R scripts into a package
- Setting up a package skeleton for collaborative development

Agent perspective → conditions for activation.

Note: Top triggers also in description frontmatter (read pre-body-load). ## When to Use = extra detail.

Got: 3-5 bullets w/ concrete observable conds.

If err: Vague ("when something needs doing") → rewrite agent perspective: observable state / user req?

Step 5: Inputs

Required vs optional. Types + defaults:

## Inputs

- **Required**: Package name (lowercase, no special characters except `.`)
- **Required**: One-line description of the package purpose
- **Optional**: License type (default: MIT)
- **Optional**: Whether to initialize renv (default: yes)

Got: Required/optional separated w/ types + defaults.

If err: Ambiguous type → add example: "Package name (lowercase, no special characters except .)".

Step 6: Procedure

Core. Each step:

### Step N: Action Title

Context sentence explaining what this step accomplishes.

\```language
concrete_code("that the agent can execute")
\```

**Expected:** What success looks like. Be specific — file created, output matches pattern, command exits 0.

**On failure:** Recovery steps. Don't just say "fix it" — provide the most common failure cause and its resolution.

Effective steps:

• Each independently verifiable
• Real code, not pseudocode
• Common path first, edge cases in "On failure"
• 5-10 steps sweet spot. <5 vague; >12 split skills.
• Real tools + cmds, not abstract

For translation:

• Target ~400 lines EN. German +10-20%, CJK more → 400 EN stays <500 translated.
• No idioms / culture-specific.
• Concise prose, short sentences translate better.

Got: 5-12 numbered steps, each w/ concrete code + **Expected:** + **On failure:**.

If err: No code → add real cmd/config. No Expected/On failure → write now. Every fail-able step needs both.

Step 7: Validation

Checklist agent runs post-proc:

## Validation

- [ ] Criterion 1 (testable, binary pass/fail)
- [ ] Criterion 2
- [ ] No errors or warnings in output

Objectively verifiable. "Code clean" bad. "devtools::check() returns 0 errors" good.

Got: Markdown checklist w/ 3-8 binary pass/fail.

If err: Subjective → measurable. "Well-documented" → "All exported fns have @param, @return, @examples roxygen tags."

Step 8: Common Pitfalls

3-6 pitfalls w/ cause + avoidance:

## Common Pitfalls

- **Pitfall name**: What goes wrong and how to avoid it. Be specific about the symptom and the fix.

Real experience. Best = waste time + non-obvious.

Got: 3-6 pitfalls, each w/ bold name + desc + avoidance.

If err: Generic ("be careful w/ X") → specific: symptom + cause + fix. Draw from real fails.

Step 9: Related Skills

Xref 2-5 used before/after/alongside:

## Related Skills

- `prerequisite-skill` - must be done before this skill
- `follow-up-skill` - commonly done after this skill
- `alternative-skill` - alternative approach to the same goal

Skill name field (kebab-case), not title.

Got: 2-5 related, kebab-case IDs + relationship.

If err: Verify: ls skills/<skill-name>/SKILL.md. Remove renamed/removed refs.

Step 10: Registry

Edit skills/_registry.yml, add under domain:

- id: skill-name-here
  path: skill-name-here/SKILL.md
  complexity: intermediate
  language: multi
  description: One-line description matching the frontmatter

Update total_skills at top.

Got: Entry under correct domain, total_skills = disk count.

If err: Count: find skills -name SKILL.md | wc -l vs registry. Verify id = dir exact.

Step 11: Citations (Optional)

Based on methods/papers/pkgs/standards → add references/:

mkdir -p skills/<skill-name>/references/

2 files:

• references/CITATIONS.bib — BibTeX (src of truth)
• references/CITATIONS.md — rendered for GitHub

% references/CITATIONS.bib
@article{author2024title,
  author  = {Author, First and Other, Second},
  title   = {Paper Title},
  journal = {Journal Name},
  year    = {2024},
  doi     = {10.xxxx/xxxxx}
}

<!-- references/CITATIONS.md -->
# Citations

References underpinning the **skill-name** skill.

1. Author, F., & Other, S. (2024). *Paper Title*. Journal Name. https://doi.org/10.xxxx/xxxxx

Optional — add when provenance matters (academic, standards, regulatory).

Handling references/ in translations: Prose in references/EXAMPLES.md → translate. references/CITATIONS.bib → English (BibTeX lang-neutral). Translations may symlink to EN references/ if code-only.

Got: Both files exist, .bib valid.

If err: Validate: bibtool -d references/CITATIONS.bib / online.

Step 12: Validate

Local checks pre-commit:

# Check line count (must be ≤500)
lines=$(wc -l < skills/<skill-name>/SKILL.md)
[ "$lines" -le 500 ] && echo "OK ($lines lines)" || echo "FAIL: $lines lines > 500"

# Check required frontmatter fields
head -20 skills/<skill-name>/SKILL.md | grep -q '^name:' && echo "name: OK"
head -20 skills/<skill-name>/SKILL.md | grep -q '^description:' && echo "description: OK"

Got: ≤500 lines, required fields present.

If err: >500 → progressive disclosure → extract code blocks (>15 lines) → references/EXAMPLES.md:

mkdir -p skills/<skill-name>/references/

Move extended examples, full configs, multi-variant → references/EXAMPLES.md. Xref in SKILL.md: See [EXAMPLES.md](references/EXAMPLES.md) for complete configuration examples. Keep inline snippets (3-10 lines). CI (.github/workflows/validate-skills.yml) enforces on PRs.

Step 13: Slash Command Symlinks

Symlinks → Claude Code discovers as /slash-command:

# Project-level (available in this project)
ln -s ../../skills/<skill-name> .claude/skills/<skill-name>

# Global (available in all projects)
ln -s /mnt/d/dev/p/agent-almanac/skills/<skill-name> ~/.claude/skills/<skill-name>

Got: ls -la .claude/skills/<skill-name>/SKILL.md resolves.

If err: Rel path correct. From .claude/skills/, ../../skills/<skill-name> reaches dir. Debug: readlink -f. Claude Code expects flat .claude/skills/<name>/SKILL.md.

Step 14: Scaffold Translations

Required for all skills. Human + AI authors. Do not skip → backlog.

4 locales post-commit:

for locale in de zh-CN ja es; do
  npm run translate:scaffold -- skills <skill-name> "$locale"
done

Translate prose (code + IDs EN). Regen:

npm run translation:status

Got: 4 files at i18n/{de,zh-CN,ja,es}/skills/<skill-name>/SKILL.md, source_commit = HEAD. npm run validate:translations → 0 stale.

If err: Scaffold fail → skill in skills/_registry.yml first (script reads registry). translation:status shows stale → source_commit = commit hash where EN src last modified.

Check

• SKILL.md at skills/<skill-name>/SKILL.md
• YAML parses
• name = dir
• description <1024 chars
• Required sections: When to Use, Inputs, Procedure, Validation, Common Pitfalls, Related Skills
• Every step has code + Expected/On failure
• Related Skills = valid names
• In _registry.yml w/ correct path
• total_skills updated
• SKILL.md ≤500 lines (extract → references/EXAMPLES.md if over)
• EN src ≤~400 lines so translations <500
• Citations in references/CITATIONS.bib + CITATIONS.md if pub methods
• Symlink at .claude/skills/<skill-name> → dir
• Global symlink at ~/.claude/skills/<skill-name> (if global)

Traps

• Vague procedures: "Configure appropriately" useless to agent. Exact cmds + paths + values.
• Missing On failure: Every fail-able step needs recovery. Agents can't improvise.
• Broad scope: "Set up entire dev env" → 3-5 focused skills. 1 skill = 1 proc.
• Untestable validation: "Code quality good" → "Linter 0 warnings".
• Stale xrefs: Rename/remove → grep old name in Related Skills.
• Desc too long: Agents read → decide activation. <1024 chars, front-load key info.
• Authoring @ 500-line limit for 1 lang: 490 lines EN → exceeds 500 translated (+10-20% German, more CJK). Target ~400 EN + progressive disclosure.
• Avoid git mv on NTFS (WSL): /mnt/ paths → git mv dirs → broken perms (d?????????). Use mkdir -p + copy + git rm old. See env guide.

Examples

Quality checklist:

1. Agent decides activation from desc alone
2. Proc mechanical, no ambiguity
3. Every step verifiable
4. Failure modes → concrete recovery
5. Composable w/ related

Size ref:

• Basic: ~80-120 lines (write-vignette, configure-git-repository)
• Intermediate: ~120-180 lines (write-testthat-tests, manage-renv-dependencies)
• Advanced: ~180-250 lines (submit-to-cran, setup-gxp-r-project)
• Extended: SKILL.md ≤500 + references/EXAMPLES.md for large configs

→

• evolve-skill — evolve + refine skills
• create-agent — parallel agent proc
• create-team — parallel team proc
• write-claude-md — CLAUDE.md refs skills
• configure-git-repository — version-control skills
• commit-changes — commit skill + symlinks
• security-audit-codebase — review for secrets