# UX Heuristics > Usability evaluation and principles — an AI agent skill based on *Don’t Make Me Think* by Steve Krug & Jakob Nielsen. Published 2026-02-19 · Updated 2026-08-17 · Design & UX · Free and MIT-licensed Canonical: https://skills.wondel.ai/skills/ux-heuristics/ Source: https://github.com/wondelai/skills/tree/main/ux-heuristics **Install:** `npx skills add wondelai/skills/ux-heuristics --global` ## What is the UX Heuristics skill? UX Heuristics folds two usability traditions into one skill: Jakob Nielsen’s ten heuristics and Steve Krug’s Don’t Make Me Think. It has your agent walk an interface the way an evaluator does — naming each violation, rating its severity from 0 to 4, and proposing the specific fix — instead of offering a general opinion on whether a screen looks usable. ## Key concepts from Don’t Make Me Think your agent applies - **Visibility of System Status** — Always keep users informed about what's going on through timely feedback. - **Recognition over Recall** — Minimize memory load by making options, actions, and information visible or easily retrievable. - **Error Prevention** — Design to prevent problems from occurring rather than relying on error messages after the fact. - **Consistency & Standards** — Follow platform conventions and maintain internal consistency throughout the interface. - **The Trunk Test** — Every page should clearly answer: Where am I? What are my options? How did I get here? ## When to use UX Heuristics — and when not to Reach for it when: - Support answers the same “where do I find…” question every week and you suspect the navigation. - Your signup form is abandoned halfway and you need to know which fields cause it. - A page looks beautiful and a first-time visitor can’t tell what the site is or where to go. - You need an audit that produces a ranked issue list, not a design opinion. Reach for something else when: - The interface is usable and simply looks unprofessional — Refactoring UI handles spacing, color, and hierarchy. - You want more signups from the same traffic — CRO Methodology tests for revenue, not comprehension. - You need real reasons from real users instead of an expert walkthrough — start with The Mom Test. - It is an iOS app and the issue is convention rather than clarity — iOS HIG Design knows what users expect. ## About Steve Krug & Jakob Nielsen Pioneering usability experts and co-founders of modern UX. Steve Krug is a usability consultant whose book "Don't Make Me Think" became the definitive guide to web usability. Jakob Nielsen co-founded Nielsen Norman Group and developed the 10 usability heuristics used industry-wide. More: https://en.wikipedia.org/wiki/Steve_Krug · https://www.wikidata.org/wiki/Q16636194 · https://en.wikipedia.org/wiki/Jakob_Nielsen_(usability_consultant) · https://www.wikidata.org/wiki/Q82556 The book: https://openlibrary.org/books/OL28651286M/Don't_Make_Me_Think_Revisited_A_Common_Sense_Approach_to_Web_Usability · https://en.wikipedia.org/wiki/Don't_Make_Me_Think · https://www.wikidata.org/wiki/Q3503996 ## Example prompts - Run a heuristic evaluation on my checkout flow using ux-heuristics skill _(UX audit)_ - Identify usability issues on this dashboard page using ux-heuristics skill _(Usability review)_ - Simplify this navigation so users don't have to think using ux-heuristics skill _(Information architecture)_ - Add better error prevention to my form validation using ux-heuristics skill _(Error handling)_ ## Frequently asked questions ### How do I install the UX Heuristics skill? Run `npx skills add wondelai/skills/ux-heuristics --global`. It takes about 30 seconds and needs no account. The UX Heuristics skill then works in Claude, Claude Code, Claude Cowork, Codex, Cursor, OpenClaw and Hermes Agent — anything that reads the open agentskills.io format — and your agent loads it on its own when a task calls for it. It is free and MIT-licensed, and the source is at https://github.com/wondelai/skills. ### Which book is the UX Heuristics skill based on? It packages *Don’t Make Me Think* by Steve Krug & Jakob Nielsen — pioneering usability experts and co-founders of modern UX. The skill distils the book's method into instructions your agent follows while it works, covering visibility of system status, recognition over recall and error prevention. It sits in the Design & UX part of the library. ### What do Nielsen’s heuristics do that Krug’s laws don’t? They do different halves of the job. Nielsen’s ten are an inspection checklist — system status, user control, error prevention, recognition over recall — designed so a reviewer covers the whole surface instead of noticing whatever catches their eye. Krug supplies the standard those violations are judged against: people scan rather than read, satisfice rather than optimise, and muddle through rather than learn. The skill enumerates with Nielsen and sets the bar with Krug. ### Can a heuristic evaluation replace user testing? No, and treating it as a substitute is the most common misuse. Expert inspection finds violations of known principles; it cannot tell you whether people want the feature, what they expected instead, or why they gave up. It was designed as a cheap pre-filter — clear the obvious problems before you spend a session on them. Krug himself argued for small, frequent tests with a handful of real users alongside it. ### How is this different from the Design of Everyday Things skill? Scope and output. Norman gives you a theory of why interaction fails at all, applicable to a stove as much as a checkout. This skill is narrower and more procedural: it walks your actual screens, tags each issue against a named heuristic, scores severity, and hands back a triage list. Use Norman when you are arguing about a design; use this when you need something a team can work through on Monday. ### Does it cover accessibility? Partly, and you should know where the line is. It flags the usability-adjacent things — unlabelled controls, low contrast, tap targets too small, focus and status that only exist visually, and dark patterns that pressure users. It is not a WCAG conformance audit and will not check your ARIA semantics or run assistive-technology testing. Treat what it finds as a floor, not a compliance report. ## Related - All Design & UX skills: https://skills.wondel.ai/skills/design/ - Refactoring UI: https://skills.wondel.ai/skills/refactoring-ui/ - iOS HIG Design: https://skills.wondel.ai/skills/ios-hig-design/ - Web Typography: https://skills.wondel.ai/skills/web-typography/ - Design of Everyday Things: https://skills.wondel.ai/skills/design-everyday-things/ - Top Design: https://skills.wondel.ai/skills/top-design/ - Lean UX: https://skills.wondel.ai/skills/lean-ux/ - Microinteractions: https://skills.wondel.ai/skills/microinteractions/ - Steve Jobs Design Review: https://skills.wondel.ai/skills/steve-jobs-design-review/