Agent-almanac review-skill-format
git clone https://github.com/pjt222/agent-almanac
T=$(mktemp -d) && git clone --depth=1 https://github.com/pjt222/agent-almanac "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/review-skill-format" ~/.claude/skills/pjt222-agent-almanac-review-skill-format-c213de && rm -rf "$T"
skills/review-skill-format/SKILL.mdReview Skill Format
Validate a SKILL.md file against the agentskills.io open standard. This skill checks YAML frontmatter completeness, required section presence, procedure step format (Expected/On failure blocks), line count limits, and registry synchronization. Use this before merging any new or modified skill.
When to Use
- A new skill has been authored and needs format validation before merge
- An existing skill has been modified and needs re-validation
- Performing a batch audit of all skills in a domain
- Verifying a skill created by the
meta-skillcreate-skill - Reviewing a contributor's skill submission in a pull request
Inputs
- Required: Path to the SKILL.md file (e.g.,
)skills/setup-vault/SKILL.md - Optional: Strictness level (
orlenient
, default:strict
)strict - Optional: Whether to check registry sync (default: yes)
Procedure
Step 1: Verify File Exists and Read Content
Confirm the SKILL.md file exists at the expected path and read its full content.
# Verify file exists test -f skills/<skill-name>/SKILL.md && echo "EXISTS" || echo "MISSING" # Count lines wc -l < skills/<skill-name>/SKILL.md
Expected: File exists and content is readable. Line count is displayed.
On failure: If the file does not exist, check the path for typos. Verify the skill directory exists with
ls skills/<skill-name>/. If the directory is missing, the skill has not been created yet — use create-skill first.
Step 2: Check YAML Frontmatter Fields
Parse the YAML frontmatter block (between
--- delimiters) and verify all required and recommended fields are present.
Required fields:
— matches directory name (kebab-case)name
— under 1024 characters, starts with a verbdescription
— typicallylicenseMIT
— comma-separated or space-separated tool listallowed-tools
Recommended metadata fields:
— author namemetadata.author
— semantic version stringmetadata.version
— one of the domains listed inmetadata.domainskills/_registry.yml
— one of:metadata.complexity
,basic
,intermediateadvanced
— primary language ormetadata.languagemulti
— comma-separated, 3-6 tags, includes domain namemetadata.tags
# Check required frontmatter fields exist head -30 skills/<skill-name>/SKILL.md | grep -q '^name:' && echo "name: OK" || echo "name: MISSING" head -30 skills/<skill-name>/SKILL.md | grep -q '^description:' && echo "description: OK" || echo "description: MISSING" head -30 skills/<skill-name>/SKILL.md | grep -q '^license:' && echo "license: OK" || echo "license: MISSING" head -30 skills/<skill-name>/SKILL.md | grep -q '^allowed-tools:' && echo "allowed-tools: OK" || echo "allowed-tools: MISSING"
Expected: All four required fields present. All six metadata fields present.
name matches directory name. description is under 1024 characters.
On failure: Report each missing field as BLOCKING. If
name does not match directory name, report as BLOCKING with the expected value. If description exceeds 1024 characters, report as SUGGEST with current length.
Step 3: Locale-Specific Validation (Translations Only)
If the frontmatter contains a
locale field, the file is a translated SKILL.md. Perform these additional checks. If no locale field is present, skip this step.
-
Translation frontmatter fields — Verify these five fields are present:
— target locale code (e.g.,locale
,de
,ja
,zh-CN
)es
— origin locale (typicallysource_locale
)en
— commit hash of the English source used for translationsource_commit
— who or what produced the translationtranslator
— ISO 8601 date of translationtranslation_date
-
Prose language scan — Sample 3-5 body paragraphs (outside code blocks, frontmatter, and headings). Verify the prose is written in the target locale, not English. Ignore: code blocks, inline code, tool names, field names, file paths, and English terms that have no standard translation in the target language.
-
Code block identity check — Compare code blocks in the translated file against the English source at
. Code blocks must be identical (code is never translated). Flag any code block whose content differs from the English source.skills/<skill-name>/SKILL.md
# Check translation frontmatter fields for field in "locale:" "source_locale:" "source_commit:" "translator:" "translation_date:"; do grep -q "^${field}\|^ ${field}" i18n/<locale>/skills/<skill-name>/SKILL.md \ && echo "$field OK" || echo "$field MISSING" done
Expected: All five translation fields present. Body paragraphs are in the target locale. Code blocks match the English source exactly.
On failure: Report missing translation fields as BLOCKING. If body paragraphs are in English despite a non-English
locale, report as BLOCKING — the file has untranslated prose. If code blocks differ from the English source, report as BLOCKING — code must not be translated or modified.
Step 4: Check Required Sections
Verify all six required sections are present in the skill body (after frontmatter).
Required sections:
## When to Use## Inputs
(with## Procedure
sub-sections)### Step N:
(may also appear as## Validation
)## Validation Checklist## Common Pitfalls## Related Skills
# Check each required section for section in "## When to Use" "## Inputs" "## Procedure" "## Common Pitfalls" "## Related Skills"; do grep -q "$section" skills/<skill-name>/SKILL.md && echo "$section: OK" || echo "$section: MISSING" done # Validation section may use either heading grep -qE "## Validation( Checklist)?" skills/<skill-name>/SKILL.md && echo "Validation: OK" || echo "Validation: MISSING"
Expected: All six sections present. Procedure section contains at least one
### Step sub-heading.
On failure: Report each missing section as BLOCKING. A skill without all six sections is non-compliant with the agentskills.io standard. Provide the section template from the
create-skill meta-skill.
Step 5: Check Procedure Step Format
Verify each procedure step follows the required pattern: numbered step title, context, code block(s), and Expected:/On failure: blocks.
For each
### Step N: sub-section, check:
- The step has a descriptive title (not just "Step N")
- At least one code block or concrete instruction exists
- An
block is present**Expected:** - An
block is present**On failure:**
Expected: Every procedure step has both Expected: and On failure: blocks. Steps contain concrete code or instructions, not vague descriptions.
On failure: Report each step missing Expected/On failure as BLOCKING. If steps contain only vague instructions ("configure the system appropriately"), report as SUGGEST with a note to add concrete commands.
Step 6: Verify Line Count
Check that the SKILL.md is within the 500-line limit.
lines=$(wc -l < skills/<skill-name>/SKILL.md) [ "$lines" -le 500 ] && echo "OK ($lines lines)" || echo "OVER LIMIT ($lines lines > 500)"
Expected: Line count is 500 or fewer.
On failure: If over 500 lines, report as BLOCKING. Recommend using the
refactor-skill-structure skill to extract code blocks >15 lines to references/EXAMPLES.md. Typical reduction: 20-40% by extracting extended examples.
Step 7: Check Registry Synchronization
Verify the skill is listed in
skills/_registry.yml under the correct domain with matching metadata.
Check:
- Skill
exists under the correct domain sectionid
matchespath<skill-name>/SKILL.md
matches frontmattercomplexity
is present (may be abbreviated)description
count at the top of the registry matches actual skill counttotal_skills
# Check if skill is in registry grep -q "id: <skill-name>" skills/_registry.yml && echo "Registry: FOUND" || echo "Registry: NOT FOUND" # Check path grep -A1 "id: <skill-name>" skills/_registry.yml | grep -q "path: <skill-name>/SKILL.md" && echo "Path: OK" || echo "Path: MISMATCH"
Expected: Skill is listed in the registry under the correct domain with matching path and metadata. Total count is accurate.
On failure: If not found in registry, report as BLOCKING. Provide the registry entry template:
- id: skill-name path: skill-name/SKILL.md complexity: intermediate language: multi description: One-line description
Validation
- SKILL.md file exists at the expected path
- YAML frontmatter parses without errors
- All four required frontmatter fields present (
,name
,description
,license
)allowed-tools - All six metadata fields present (
,author
,version
,domain
,complexity
,language
)tags -
field matches directory namename -
is under 1024 charactersdescription - All six required sections present (When to Use, Inputs, Procedure, Validation, Common Pitfalls, Related Skills)
- Every procedure step has Expected: and On failure: blocks
- Line count is 500 or fewer
- Skill is listed in
with correct domain, path, and metadata_registry.yml -
count in registry is accuratetotal_skills - (Translations only) All five translation frontmatter fields present (
,locale
,source_locale
,source_commit
,translator
)translation_date - (Translations only) Body paragraphs are in the target locale, not English
- (Translations only) Code blocks are identical to the English source
Common Pitfalls
- Checking frontmatter with regex only: YAML parsing can be subtle. A
multiline block looks different fromdescription: >
. Check both patterns when searching for fields.description: "inline" - Missing the Validation section variant: Some skills use
instead of## Validation Checklist
. Both are acceptable; check for either heading.## Validation - Forgetting registry total count: After adding a skill to the registry, the
number at the top must also be incremented. This is a common miss in PRs.total_skills - Name vs. title confusion: The
field must be kebab-case matching the directory name. Thename
heading is human-readable and can differ (e.g., name:# Title
, title:review-skill-format
).# Review Skill Format - Lenient mode skipping blockers: Even in lenient mode, missing required sections and frontmatter fields should still be flagged. Lenient mode only relaxes style and metadata recommendations.
- Translated skills with English prose: A file with non-English frontmatter, non-English headings, and English body paragraphs passes all structural checks. Always verify body text language for translated skills — the
field in frontmatter signals that prose must be in the target language, not English.locale
Related Skills
— The canonical format specification; use as the authoritative reference for what a valid SKILL.md looks likecreate-skill
— After format validation passes, use this to improve content qualityupdate-skill-content
— When a skill fails the line count check, use this to extract and reorganizerefactor-skill-structure
— When reviewing a PR that adds or modifies skills, combine PR review with format validationreview-pull-request