Impeccable
pbakaus/impeccableA design skill with 24 commands (polish, bolder, critique, audit, harden and more), a 62-rule deterministic slop detector and an optional edit hook.
With caveats
Broad access Depth 4/5
web-design-guidelines skill
A one-page Vercel skill that fetches Vercel's Web Interface Guidelines at run time and checks your UI files against them, reporting terse file:line findings.
Our verdict Recommended with caveats
Useful and well-known (about 800,000 installs), but the skill is only a pointer to a remote file that is fetched unpinned on every run.
What the web-design-guidelines skill does
web-design-guidelines is a review skill with no rules of its own. When you ask it to review your UI, check accessibility, audit design or review UX, the agent fetches a command file from the vercel-labs/web-interface-guidelines repository on GitHub, reads the files or glob pattern you name (or asks which to review), applies every rule from the fetched text and prints findings in the terse file:line format the guidelines define.
The skill folder contains a single SKILL.md of about 1.2 KB. Everything of substance lives in the remote file. The Vercel repo README describes more than 100 rules covering accessibility, focus states, forms, animation and reduced motion, typography, images, performance, navigation and state, dark mode, touch behavior and locale formatting. Because the rules are pulled from the main branch each time, you always get the current version, but the review also depends on network access and on that remote file staying intact. It is a single-purpose reviewer rather than a design generator: it audits code you already have and does not write components.
Good for
- Quick accessibility and UX pass over a React or HTML component before a pull request
- Teams that want Vercel's interface rules applied consistently without copying them into the repo
Not for
- Offline or restricted-network environments
- People who want rules pinned to a version for reproducible reviews
Depth 1/5
A single 1.2 KB SKILL.md with no references or scripts; the actual rules are in a separate repository fetched at run time.
Dependencies and costs
- Network access to raw.githubusercontent.com for the guidelines file
- Telemetry: none found. The only outbound request is the fetch of the guidelines file.
Security review
Broad accessThis skill asks for more access than most, or sends data to another service. That is usually a design choice rather than bad intent, but you should know before you install it.
- Loads instructions from a server at run timeTells the agent to WebFetch https://raw.githubusercontent.com/vercel-labs/web-interface-guidelines/main/command.md before each review and apply the fetched rules and output format; the URL is an unpinned main branch.SKILL.md:26
A single SKILL.md with no scripts. At each run it fetches the review rules from a Vercel GitHub repository's main branch and follows them, so its effective instructions can change without a change to this skill.
Worth knowing
- Makes network requestsThe only network request is that WebFetch of the guidelines file.SKILL.md:29
What we checked
The skill folder (1 files) on Oct 29, 2026. Not a full review: it relies on code outside the repository: Content served at runtime from raw.githubusercontent.com/vercel-labs/web-interface-guidelines/main/command.md.
NVIDIA SkillSpector static scan: 0 pattern hits. SkillSpector reported no hits for this skill folder.
A review, not a certification. Skills change after we check them — read the files before installing.
License
No license stated in the skill folder; the parent repository's README says MIT.
Can it run unattended?
Not really. It is a one-shot review that asks which files to check if none are given.
Alternatives
Hallmark
Nutlope/hallmarkA design skill from Together AI that deals a theme from 50 options, builds pages around the visitor's goal and lints the result in a real browser for AI-looking tells.
Recommended
Check first Depth 5/5
Web Quality Skills
addyosmani/web-quality-skillsSix skills by Addy Osmani for auditing and fixing web performance, Core Web Vitals, accessibility, SEO and best practices, built around Lighthouse.
Recommended
Check first Depth 3/5
UI Skills
ibelick/ui-skillsNine skills for design engineers: a UI baseline checklist, accessibility/metadata/motion fixers, a design.md generator, and canvas builders for components.
Recommended
Broad access Depth 2/5
FAQ
What is the web-design-guidelines skill?
It is a Vercel skill that reviews UI code against Vercel's Web Interface Guidelines. It fetches the rules from GitHub, checks the files you point it at, and lists problems with file and line.
How do I install web-design-guidelines?
Run npx skills add vercel-labs/agent-skills and select web-design-guidelines. Then ask the agent to review your UI and give it a file or pattern.
Is web-design-guidelines safe?
It has no scripts, but it makes the agent fetch and follow a remote markdown file from Vercel's GitHub on each run. Trust depends on that repository, and the rules can change without the skill changing.
web-design-guidelines vs impeccable: which should I use?
web-design-guidelines is a compliance checker against one published rule set. Impeccable is a broader design vocabulary with commands for critique and polish. Use the Vercel skill for a fixed checklist and the other for design direction.
Sources: GitHub repository; install counts from skills.sh via Best Skills (CC BY 4.0). Review based on the published SKILL.md.