design

A question-based review method for designing user interfaces, including their layout, navigation, states, and behavior on different platforms. It adapts its terms to the project’s existing UI toolkit, if one exists.

In plain words
What is it for?
It helps plan or critique screens and user flows. It asks about the main action, entry point, component choices, design system, and platform behavior.
Why use it?
It helps uncover unclear goals, poor screen composition, and missing interface states before or during implementation.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/tiltely/lens/design
Any agent
npx skills add Tiltely/lens --skill design
Clone the repo
git clone --depth 1 https://github.com/Tiltely/lens

Made for: Claude Code, Codex.

Per session 90 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,251 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00090 $0.01251
Opus 5 $0.00045 $0.00626
Sonnet 5 $0.00018 $0.00250
Haiku 4.5 $0.00009 $0.00125

Measured 2d ago against content hash d2fe51cda25b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

design 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 2d 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/design/SKILL.md · 105 lines

How it starts

The opening of the file, as written. The whole thing — 105 lines — stays where its author put it; the contents beside it link to each section on GitHub.

The Lens of Interface Design

Read first: ${CLAUDE_PLUGIN_ROOT}/core/protocol.md and ${CLAUDE_PLUGIN_ROOT}/core/dossier.md. Dossier rules: read it, skip answered questions WITH skip lines, append your outputs.

This lens is technology-agnostic (protocol.md, "Lens agnosticism"). Component vocabulary adapts to whatever the project uses — the questions do not change.

Detect the design system (before Tier 2)

Inspect the project once and record design-system: in the dossier:

  • components.json + a ui/ components dir → shadcn/ui
  • @mui/material → MUI · @chakra-ui/* → Chakra · antd → Ant Design
  • Tailwind only, no component library → utility-first custom
  • none of the above → no design system (candidates come from platform primitives; Tier 3 asks whether adopting one pays off)

Question battery — design mode

Tier 1 — framing (always)

  1. What is the ONE primary action on this screen? (If the answer lists three, dig: which one does the business need most?)
  2. Who lands here and from where? (entry point shapes layout: deep link ≠ nav click)

Tier 2 — composition

  1. Component candidates: for the core interaction, name 2–3 compositions in the project's design system (or platform primitives if none) that could serve it — e.g., modal vs slide-over panel vs dedicated route; tabs vs accordion vs stepper. RANK them against: mobile ergonomics, state preserved on navigation, implementation cost. Recommend one, with the ranking visible.
  2. Where does this screen's navigation live — and is that consistent with the rest of the app? (nav items, tabs placement, back behavior on mobile web)
  3. Which states exist beyond happy path — loading, empty, error, partial? Show what each looks like (skeleton? empty-state CTA? toast vs inline error?).
  4. Does this app ship as a PWA, or will it? → load the depth pack ${CLAUDE_PLUGIN_ROOT}/skills/design/topics/pwa.md and run its battery.

Tier 3 — deep dives (only when triggered)

  • Forms involved → field-level validation timing (on blur? on submit?), error placement, and what happens to user input on failure.
  • Data tables/lists → empty, 1 item, 10k items: same component?
  • Dark mode shipped → are the chosen components token-driven or hardcoded colors?
  • No design system detected → is it time to adopt one? What does consistency cost today vs the migration cost?

Read the full file on GitHub · 105 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 2d ago First seen · 105 lines · 90 tokens per session scan A d2fe51cda25b

Subscribe to this mod's changes

design is a skill published in the GitHub repository Tiltely/lens (5 stars, last pushed 23d ago), licensed MIT. It adds 90 tokens to every session and 1,251 once invoked, about $0.0005 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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