Nine skills that carry a product engagement from a raw brief to a developer handoff. They encode one designer's method — Mikel Rosenthal, 23 years, five design systems built from scratch — so the output is the same shape whoever runs it.
Install
Copy the skills/ directory into your Claude project. Each subdirectory is one skill. Claude reads only the description line of each SKILL.md until a task matches, so the whole library costs almost nothing at rest.
Paste PROJECT-INSTRUCTIONS.md into the project's instructions so the house rules apply to everything, not only to skill invocations.
Start here
| File | What it's for |
|---|---|
DEMO.md | A ten-minute live demo runbook, with the exact prompts to type |
PROJECT-INSTRUCTIONS.md | Project-level instructions carrying the five house rules |
examples/ | Seven finished artifacts, so the templates aren't the only thing anyone sees |
The order they run in
| Phase | Skill | Produces |
|---|---|---|
| Intake | brief-intake | The structured project file |
| Evaluate (track A) | ds-inventory | Component inventory, token diff, drift report |
| Evaluate (track B) | heuristic-audit | Severity-rated findings against a live product |
| Evaluate | research-synthesis | Ten insights, each with a design implication |
| Map | flow-map | Flows plus the full state matrix |
| Design | copy-standards | Errors, empty states, labels in the product's voice |
| Design | a11y-spec | Focus order, roles, contrast pairs per screen |
| Design | critique | An argument against the work before the team sees it |
| Hand off | handoff-spec | The developer package |
Two entry points
Evaluating a design system is a counting exercise before it is a taste one — start with ds-inventory, on what actually ships.
A product overview is a people exercise — start with research-synthesis and heuristic-audit, because a perfectly consistent product can still be the wrong one.
brief-intake runs before either.
House rules every skill inherits
- Never invent a number. Every quantity traces to a named source, or it is cut.
- Say what you could not determine. An honest gap beats a confident guess.
- Attach a cost to every finding. Findings without a cost are trivia.
- Recommend, don't enumerate. One recommendation, its trade, and the rejected alternative.
- Output is a file, not a chat reply. Written artifacts are what survive the call.