check-design-system

check-design-system is a skill for Claude Code, Codex from stunt-double/stuntdouble-mcp. It costs 46 tokens per session (819 once invoked), scanned A, original, MIT.

A review of a live product against its design system—the shared rules for colours, fonts, spacing, components, and icons. It records evidence when rendered pages differ from those rules.

In plain words
What is it for?
Use it to audit live pages for correct typography, colours, spacing, components, and icons against documented design-system rules.
Why use it?
It finds visual inconsistencies that arise when screens are built independently. It can also check the product again when the shared design library changes.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to audit live pages for correct typography, colours, spacing, components, and icons against documented design-system rules.

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Install with agentmods
npx agentmods add skills/stunt-double/stuntdouble-mcp/check-design-system
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add stunt-double/stuntdouble-mcp --skill check-design-system
Clone the repo
git clone --depth 1 https://github.com/stunt-double/stuntdouble-mcp

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for check-design-system

README.md
[![agentmods](https://agentmods.dev/badge/skills/stunt-double/stuntdouble-mcp/check-design-system/github.svg)](https://agentmods.dev/skills/stunt-double/stuntdouble-mcp/check-design-system)
Your own site
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Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for check-design-system

Your own site · 80×15
<a href="https://agentmods.dev/skills/stunt-double/stuntdouble-mcp/check-design-system"><img src="https://agentmods.dev/badge/skills/stunt-double/stuntdouble-mcp/check-design-system.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 46 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 819 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00046 $0.00819
Opus 5 $0.00023 $0.00409
Sonnet 5 $0.00009 $0.00164
Haiku 4.5 $0.00005 $0.00082

Measured 9d ago against content hash 25abe6685875, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

check-design-system scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/check-design-system/SKILL.md · 66 lines

How it starts

The opening of the file, as written. The whole thing — 66 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Check design system

When to use

  • You have a design system (tokens, component rules, a Figma library) and want to know where the live product drifts from it
  • Screens shipped independently and visual consistency has eroded
  • You want design-system adherence enforced when the library is published or files change

Instructions

  1. Resolve context:

    • list_workspaces() → pick the workspace
    • list_projects(workspace_id) → match the URL to a project, or let create_checklist find/create it
  2. Set up a design-guardian actor and record the rules:

    • list_actors(workspace_id), else create_actor(...) described as a design-system reviewer
    • list_workspace_guidelines(workspace_id) first, then either attach an existing rule with set_project_guideline(project_id, guideline_id) or write one with add_project_guideline(project_id, category: "design_system", content, title). Token values and component dos and don'ts belong here: guidelines reach every run and design review for the project
    • update_workspace_guideline(workspace_id, guideline_id, apply_to_design_reviews: true) when the standard should also hold for design reviews raised from Slack or Linear, which carry no project
    • If no rules were supplied, ask for the key tokens and component rules, or derive a draft from the most polished screens and confirm it
  3. Create a checklist per surface:

    • Actors see the rendered product the way a user does, so phrase checks visually, not in terms of code or class names:
      • "Body text uses the product font stack, no serif fallbacks anywhere"
      • "Primary CTAs use the brand primary colour and sentence case"
      • "Form fields show a visible focus state"
      • "Empty states use the illustration style, not stock icons"
      • "Spacing between sections is consistent across pages"
  4. Run and collect evidence:

    • run_checklist(checklist_id) → poll get_checklist_run(run_id) until terminal; collect evidence for each deviation

Read the full file on GitHub · 66 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 66 lines · 46 tokens per session scan A 25abe6685875

Subscribe to this mod's changes

check-design-system is a skill published in the GitHub repository stunt-double/stuntdouble-mcp (1 stars, last pushed 24d ago), licensed MIT. It adds 46 tokens to every session and 819 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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