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.
npx skills add stunt-double/stuntdouble-mcp --skill check-design-systemgit clone --depth 1 https://github.com/stunt-double/stuntdouble-mcpWrote 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.
[](https://agentmods.dev/skills/stunt-double/stuntdouble-mcp/check-design-system)<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/github.svg" alt="Measured on agentmods" height="20"></a>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.
<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>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.
| Model | Per session | Once 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 |
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.
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
-
Resolve context:
list_workspaces()→ pick the workspacelist_projects(workspace_id)→ match the URL to a project, or letcreate_checklistfind/create it
-
Set up a design-guardian actor and record the rules:
list_actors(workspace_id), elsecreate_actor(...)described as a design-system reviewerlist_workspace_guidelines(workspace_id)first, then either attach an existing rule withset_project_guideline(project_id, guideline_id)or write one withadd_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 projectupdate_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
-
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"
- Actors see the rendered product the way a user does, so phrase checks visually, not in terms of code or class names:
-
Run and collect evidence:
run_checklist(checklist_id)→ pollget_checklist_run(run_id)until terminal; collect evidence for each deviation
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.
- 9d ago First seen · 66 lines · 46 tokens per session scan A 25abe6685875
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.
Other skills, from other repositories
frontend-ui-engineering
Builds production-quality, accessible, responsive user-facing UIs. Use when building or modifying interfaces and pages, creating components, implementing layouts, meeting WCAG accessibility requirements, managing state, or when the output needs to look and feel production-quality rather than AI-generated.
brand-landingpage
Brand-first landing page designer — runs a brand-identity interview (colors, typography, shape language), then generates and iterates on a polished landing page via Stitch with deployment-ready HTML. Use when the user asks to create, design, or build a landing page, homepage, or marketing page and has no established…
21st-ui
Find, install, and generate UI with 21st.dev. Use when the user asks for a UI component (pricing table, hero, navbar, dashboard, form, etc.), wants design inspiration, needs a brand logo as an SVG component, or wants to generate new UI from a prompt.
tailwind-design-system
Build scalable design systems with Tailwind CSS v4, design tokens, component libraries, and responsive patterns. Use when creating component libraries, implementing design systems, or standardizing UI patterns.
interaction-skill
Layer A interaction-mechanics reference anchored to the beui.dev catalog. Stacks on any style skill whenever work adds or changes motion or interaction — micro-interactions, animated components, transitions, gestures, hover/press/state feedback, loading/success/error morphs, 'make it feel alive'. Mandates reading the…
layout-skill
Layer A layout-mechanics reference. Stacks on any style skill when the screen is an app shell, dashboard, settings, list-detail, mail/inbox, or any layout with fixed regions plus a scrolling body — or when a layout breaks under long, empty, or unbroken content. Owns spatial structure and scroll ownership; owns zero…