Runs deterministic validation script - Fast, consistent checking of all links
Generates structured report - JSON output with all issues found
Spawns fixer subagent - AI-powered fix suggestions for issues
Presents fix plan - Diff-style changes for approval
Executes approved fixes - Only applies changes user approves

Validation Checks

Check Type	Description
External URLs	HTTP HEAD request to verify accessibility
Skill references	Verify referenced skills exist (e.g., `umbraco-dashboard`)
Internal links	Check relative paths resolve (e.g., `patterns/foo.md`)
File paths	Verify Umbraco-CMS paths via GitHub API if not local
Import paths	Check `@umbraco-cms/backoffice/*` imports are valid

Running the Validator

Via Slash Command

/validate-skills

Via Script Directly (CI/CD)

cd .claude/skills/umbraco-skill-validator/scripts
npm install
npm run validate

Report Format

The script outputs JSON that gets formatted as:

# Skill Validation Report

## Summary
- Skills scanned: 25
- Issues found: 3
- Auto-fixable: 2

## Issues by Skill

### `umbraco-dashboard`
| Line | Type | Issue | Status |
|------|------|-------|--------|
| 45 | Broken URL | [example-broken-url] returns 404 | :x: |

### `umbraco-tree`
| Line | Type | Issue | Status |
|------|------|-------|--------|
| 72 | Missing skill | [example-missing-skill] not found | :x: |

Fix Plan Format

When issues are found, the fixer subagent generates:

# Fix Plan

## Fix 1: Update broken URL
**File:** plugins/.../umbraco-dashboard/SKILL.md
**Line:** 45
**Action:** Replace with current documentation URL

- [Dashboard docs][old-url]
+ [Dashboard docs][new-url]

## Approval
- [ ] Fix 1: Update broken URL
- [ ] Fix 2: ...

Link Patterns Detected

External URLs

https://docs.umbraco.com/...
https://github.com/umbraco/...

Skill References

`umbraco-dashboard`
`umbraco-workspace`

Internal Pattern Links

[Pattern Name](patterns/pattern-name.md)
[Example](examples/example-name/)

File Paths

/Umbraco-CMS/src/Umbraco.Web.UI.Client/...
src/packages/core/...

Import Paths (in code blocks)

import { ... } from '@umbraco-cms/backoffice/notification';

Workflow Instructions

When this skill is invoked:

Run the validation script

``bash cd .claude/skills/umbraco-skill-validator/scripts npx tsx validate-links.ts ``

Read the JSON output from stdout or validation-report.json

Format as markdown report using the template above

If issues found, spawn the skill-content-fixer agent:

- Pass the JSON report as context - Request fix suggestions with diffs

Present fix plan to user with AskUserQuestion

Execute only approved fixes using Edit tool

Edge Cases

Rate limiting: Script batches URL checks with 100ms delays
Redirects: Reported as warnings with new URL suggestion
Missing Umbraco-CMS: Falls back to GitHub API
Timeouts: 5 second timeout per URL request
Large repos: Processes files in batches of 10

npx skills add umbraco/umbraco-cms-backoffice-skills --skill umbraco-skill-validator