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 connerkward/deterministic-design-skill --skill design-uxgit clone --depth 1 https://github.com/connerkward/deterministic-design-skillWrote 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/connerkward/deterministic-design-skill/design-ux)<a href="https://agentmods.dev/skills/connerkward/deterministic-design-skill/design-ux"><img src="https://agentmods.dev/badge/skills/connerkward/deterministic-design-skill/design-ux/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/connerkward/deterministic-design-skill/design-ux"><img src="https://agentmods.dev/badge/skills/connerkward/deterministic-design-skill/design-ux.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 | $0.00112 | $0.01549 |
| Opus 5.5 | $0.00045 | $0.00620 |
| Sonnet 5.5 | $0.00022 | $0.00310 |
| Haiku 4.5 | $0.00011 | $0.00155 |
Grade A, and why
design-ux 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 1mo 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.
This is a copy
100% identical to design-ux — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.
design-ux — usability audit (heuristic evaluation)
Usability ≠ aesthetics. design-system/design-spatial make it look right; this checks whether a first-timer can do the task without being told how. Use it whenever a UI "sucks to use," needs a paragraph of instructions, or before shipping anything interactive.
Rule 0 — fresh eyes, on the rendered artifact (inherited from design-spatial §1)
Never self-grade. The builder rationalizes its own UI. Render the live UI in its default first-load state (not a hand-arranged screenshot), capture an interaction trace of the primary task, and have a separate judge (a subagent/VLM that did NOT build it) score it. A described list of changes is not an audit — the audit is a fresh judge hunting for what's wrong on the real screen.
The procedure
- Name the primary task(s) the UI exists for (e.g. "trim a clip and set its speed, then export"). The audit is relative to these, not to abstract prettiness.
- Render default state + trace the task. Screenshot the first-load UI (wide AND narrow — overflow gate from design-spatial §2). Then actually perform the primary task and screenshot each step.
- Score every heuristic (table below) on the artifact: pass / violation, severity (blocker / major / minor), a specifically located finding, and a concrete fix. Separate judge does this.
- Prioritize: blockers → majors → minors; cluster fixes that touch the same surface.
- Fix, then RE-RENDER and RE-SCORE. Do not claim fixed without re-auditing the new artifact (verify-outputs-rule).
Heuristics — score each (Nielsen's 10, 1994) + interaction add-ons
| # | Heuristic (Nielsen) | What to check in THIS UI |
|---|---|---|
| 1 | Visibility of system status | Every action has visible feedback; current state/selection/mode always legible; progress for slow ops. |
| 2 | Match the real world | Known metaphors & conventions (e.g. NLE: clips, trim handles, playhead) — not bespoke gestures users must learn. |
| 3 | User control & freedom | Undo/redo, cancel, clear exits from any state; reversible by default. |
| 4 | Consistency & standards | Same thing looks/behaves the same; platform conventions (⌘Z, Delete, drag-to-move) honored. |
| 5 | Error prevention | Invalid states made impossible; destructive actions confirmed or trivially undoable. |
| 6 | Recognition over recall | Options/affordances visible — no memorizing. An instruction wall is a failure of this heuristic: if you must explain scroll-to-zoom / drag-edge / double-click in prose, the affordance is missing. |
| 7 | Flexibility & efficiency | Defaults carry novices; shortcuts/accelerators for experts; sensible first-run with nothing configured. |
| 8 | Aesthetic & minimalist | Signal over chrome; no irrelevant elements competing; the primary surface carries the most visual weight. |
| 9 | Recognize/diagnose/recover from errors | Plain-language errors (not raw stderr), and a path out. |
| 10 | Help & documentation | Rarely needed if 1–9 hold; task-oriented, in-context, not a top-of-page lecture. |
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.
- 1mo ago First seen · 59 lines · 112 tokens per session scan A 46781b7d9927
design-ux is a skill published in the GitHub repository connerkward/deterministic-design-skill (4 stars, last pushed 4mo ago), licensed MIT. It adds 112 tokens to every session and 1,549 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to design-ux, differing in 0 lines, and is treated as a copy.
Other skills, from other repositories
design-spatial
Spatial composition and layout for frontend design. Load with design when composing pages/dashboards/components, or whenever generated UI looks off — overlapping/colliding elements, weak hierarchy, or generic ("looks like every startup site"). The core idea: a model can't trust its own layout, so render it, critique…
design-system
Mechanical implementation invariants for frontend design: token architecture, typography hierarchy, loading order, FOUT prevention, chrome stability, motion timing, color semantics. Use with design when building components, pages, or design systems. (Aesthetic direction lives in design-thinking; anti-trend/anti-slop…
ckw-design
Entry point for frontend design. Use WHENEVER building or touching the look of any web UI — components, pages, dashboards, landing pages, React/Vue/HTML-CSS — and whenever the user says "make this look better/nicer", "fix the spacing/layout", or mentions styling, color, typography, fonts, responsive design, polish, or…
design-thinking
Direction and intent for frontend design. Use with design when defining purpose, tone, domain, color world, and review bar; includes cross-domain lens from cinema, architecture, marketing, UX, automotive, industrial design.
design-ux
UX / usability audit — heuristic evaluation of INTERACTIVE UIs (not just visual polish). Load with design when a UI "feels off", "sucks to use", is hard to learn, needs an instruction wall, or before shipping an interactive tool/editor/app. Scores the RENDERED UI against Nielsen's 10 + interaction heuristics via a…
design-philosophy
Visual philosophy and art-direction for frontend. Use when creating high-concept work, campaigns, or when the user asks for a visual philosophy, manifesto, or unmistakable art-like aesthetic.