Don't Make Me Think — Usability Review & Redesign

Evaluate and improve UIs through Steve Krug's "Don't Make Me Think" principles. The report itself must practice what Krug preaches: scannable, visual, zero fluff. A human should skim it in 30 seconds; an AI agent should be able to parse it and start fixing.

When to Use

Trigger this skill when the user asks for a usability audit, UX review, or UI feedback on a screenshot, live URL, or HTML/CSS code. Do not use for visual/brand critique, WCAG accessibility audits, or backend/API review — route those elsewhere.

Instructions

Follow this workflow to keep the agent's context budget tight:

1. Check Prerequisites — confirm input type and access (see below).
2. Process Input — handle per the Input Handling table.
3. Evaluate — apply applicable lenses from The Ten Lenses (see references/krug-principles.md for token-efficient deep dives).
4. Generate Report — use the Report Format template verbatim.
5. Redesign (optional) — only if user requests fixes; always confirm before destructive edits.

Prerequisites

• Browser access: /browse skill available for live URL analysis
• Input available: one of — live URL, screenshot/image, HTML/CSS code, wireframe, or verbal description
• Code editor access (Redesign Mode only): write permission to the UI source files being modified

Input Handling

Input type	Action
Screenshot/image	Analyze visually
Live URL	Use /browse to navigate, screenshot, interact
HTML/CSS/JS code	Read code, focus on user experience
Wireframe/mockup	Focus on information architecture, not polish
Verbal description	Ask clarifying questions first

The Ten Lenses

Evaluate through whichever lenses apply. Read references/krug-principles.md for deep detail on any principle.

#	Lens	Core question
1	Self-evidence	Would a user pause to figure out what this is or does?
2	Scanning	Can you grasp the page structure in 2-3 seconds?
3	Visual hierarchy	Does visual weight match importance?
4	Word economy	Does every word earn its place?
5	Navigation	Do you always know where you are and how to move?
6	Trunk test	Drop here cold — can you answer: what site? what page? what can I do?
7	Landing clarity	Within 5 seconds, can you explain what this site does?
8	Affordances	Is it instantly clear what's clickable/tappable?
9	Mobile	Touch targets, reachability, no hidden gestures?
10	Goodwill	Does the UI respect the user's time and trust?

Report Format

The review output must be concise, visual, and skimmable. Think bullet points, tables, and diagrams — not paragraphs. The report serves two audiences simultaneously: a human who wants to skim in 30 seconds, and an AI agent who needs enough context to implement fixes.

Use this exact template:

# Usability Review: [Page/Screen Name]

## Thinking Cost: [LOW | MODERATE | HIGH]

> [One sentence: what's the single biggest usability problem on this page]

## Scorecard

Rate each applicable lens 0-10. Use a mermaid chart to visualize.

```mermaid
xychart-beta
  title "Usability Scores"
  x-axis ["Self-evident", "Scanning", "Hierarchy", "Words", "Navigation", "Trunk test", "Landing", "Affordances", "Mobile", "Goodwill"]
  y-axis "Score" 0 --> 10
  bar [8, 6, 5, 4, 7, 8, 9, 6, 7, 5]
```

| Lens | Score | Why |
|---|---|---|
| Self-evidence | 8/10 | Labels are clear, one ambiguous nav item |
| ... | ... | ... |

## Issues

Use severity icons: 🔴 Critical, 🟡 Moderate, 🟢 Minor

### 🔴 [Short issue title]
- **Problem:** [one line — what the user experiences]
- **Impact:** [one line — what happens because of this]
- **Fix:** [one line — specific, actionable, concrete]
- **Where:** [element/section/selector if applicable]

### 🟡 [Short issue title]
...

### 🟢 [Short issue title]
...

## Issue Map

Show where issues cluster on the page using a mermaid diagram.

```mermaid
graph TD
  subgraph Header/Nav
    I1["🔴 Duplicate 'macOS' label"]
  end
  subgraph Hero
    OK1["✅ Clear tagline"]
  end
  subgraph Mid-page
    I2["🟡 Tab selector too subtle"]
    I3["🟡 23 carousel images"]
  end
  subgraph Bottom
    I4["🔴 Disabled buttons, no explanation"]
    I5["🟡 No pricing shown"]
  end
  style I1 fill:#ff4444,color:#fff
  style I4 fill:#ff4444,color:#fff
  style I2 fill:#ffbb33,color:#000
  style I3 fill:#ffbb33,color:#000
  style I5 fill:#ffbb33,color:#000
  style OK1 fill:#00C851,color:#fff
```

## Page Flow Analysis

When relevant, show the user's journey and where friction occurs.

```mermaid
graph LR
  A["Land on page"] --> B["Read hero ✅"]
  B --> C["Scroll features ✅"]
  C --> D["See carousel 🟡"]
  D --> E["Reach CTA"]
  E --> F["Button disabled 🔴"]
  F --> G["Abandon ❌"]
  style F fill:#ff4444,color:#fff
  style G fill:#ff4444,color:#fff
  style B fill:#00C851,color:#fff
  style C fill:#00C851,color:#fff
```

## What Works

Bullet list — protect these during redesign:
- ✅ [Good thing 1]
- ✅ [Good thing 2]

## Fix Priority

| Priority | Issue | Effort | Impact |
|---|---|---|---|
| 1 | [issue] | Low | High |
| 2 | [issue] | Medium | High |
| 3 | [issue] | Low | Medium |

Report Rules

• No paragraphs. Use bullet points, tables, and mermaid diagrams.
• One line per finding. Problem, impact, fix — each one line max.
• Be specific. "Move price next to download button" not "improve transparency."
• Include selectors/locations. An AI agent reading this should know exactly where to look.
• Diagrams over descriptions. If you can show it in a mermaid chart or flowchart, do that instead of writing about it.
• Severity is visual. 🔴🟡🟢 — no walls of text explaining severity levels.
• Scores are honest. A 10/10 means flawless. Most things are 5-8. Don't grade inflate.

Redesign Mode

When the user wants fixes applied (not just reported), every destructive edit requires an explicit dry-run preview and user confirmation before writing:

1. Produce the review first (same format above).
2. Dry-run first — show the planned diff (file path, selector, before/after) and wait for explicit user confirmation. Treat unconfirmed edits as a backup safety check; never write without an approval.
3. Fix critical (🔴) issues first, then moderate (🟡).
4. Change the minimum necessary — surgical, not a rewrite.
5. Preserve brand/aesthetic — make it more intuitive, not different.
6. After each fix, show before/after; if a write fails, rollback by reverting the file from git.

If working with code, edit files directly only after confirmation. For screenshots, provide specs an AI agent or developer can implement without guessing.

Error Handling

Situation	Action
/browse fails or URL is unreachable	Ask user for a screenshot or HTML export; do not proceed with assumptions
Screenshot cannot be loaded or parsed	Ask user to re-share as PNG/JPEG or paste the relevant HTML
HTML/CSS code is incomplete	Note missing sections in the review; evaluate only what is present
No input provided	Ask for one of: URL, screenshot, code snippet, or verbal description before starting
Redesign Mode — file not writable	Report the permission issue; provide specs as code comments instead

Expected Output

A completed usability review delivers a structured Usability Review markdown report containing:

• Thinking Cost rating (LOW / MODERATE / HIGH)
• Scorecard table with 0-10 scores per applicable lens
• Issues list with 🔴🟡🟢 severity icons, one-line problem/impact/fix per item
• Issue Map mermaid diagram showing where problems cluster
• Fix Priority table ordered by effort/impact

Example summary line:

Thinking Cost: HIGH — 3 critical issues found (disabled button, missing nav labels, no landing clarity)

Edge Cases

Scenario	Handling
Input is a verbal description only	Ask clarifying questions before evaluating; do not guess at UI elements not described
Screenshot of a native mobile app (not web)	Apply mobile-specific lenses (9 — Mobile) with extra weight; note platform-specific conventions
User wants "just a quick check"	Deliver a condensed review (top 3 issues only) rather than the full 10-lens report
Redesign Mode on a CSS framework (Tailwind, Bootstrap)	Preserve the framework classes; only change values, not the framework itself
UI has no issues	Output the scorecard with high scores and a "What Works" section only; do not fabricate problems

Acceptance Criteria

• Review covers all applicable lenses from The Ten Lenses table
• Every issue entry includes Problem, Impact, Fix, and Where fields (one line each)
• Mermaid Issue Map diagram is included showing issue locations on the page
• Fix Priority table is sorted by impact (highest first)
• Redesign Mode shows a before/after for each fix applied
• Report is skimmable in 30 seconds — no long paragraphs, tables and bullets only

Step Completion Reports

After each major phase, emit a status report. See references/step-completion-reports.md for the template and per-phase check names.

Working With Live Sites

1. Navigate to the page, take screenshots
2. Interact with key elements (buttons, nav, forms)
3. Check responsive behavior
4. Produce the review based on real interaction