critique-usability

name	critique-usability
description	Reviews HTML or markdown UI specs, wireframe write-ups, and page mockups against Nielsen's 10 usability heuristics: system status, user control and exits, consistency, error prevention and recovery, recognition over recall, and minimalist design. Judges the interface's flow, controls, and states, not the wording of error or empty-state message text (critique-microcopy covers that), and not conformance against accessibility standards such as contrast or screen-reader access (critique-accessibility covers that). Use when the user asks for a usability review, design feedback, a second opinion, a red-line pass, a heuristic evaluation, or a quality check on a screen, a flow, or an interface spec before it goes to build. Covers static specs and mockups, not live running applications.
version	0.1.0
license	Apache-2.0
rubric_sources	[{"id":"NNG-HEURISTICS","citation":"Nielsen, J. (1994). Heuristic Evaluation. In Nielsen, J. and Mack, R. L. (Eds.), Usability Inspection Methods, pp. 25-62. New York: John Wiley & Sons. ISBN 0-471-01877-5. Living reference: 10 Usability Heuristics for User Interface Design, Nielsen Norman Group, published 1994-04-24, last updated 2024-01-30.","url":"https://www.nngroup.com/articles/ten-usability-heuristics/","accessed":"2026-07-31T00:00:00.000Z","operationalization":"paraphrased"},{"id":"NNG-SEVERITY","citation":"Nielsen, J. (1993). Usability Engineering, ch. 4 sec. 4.9 (Interface Evaluation), heuristics in ch. 5. Boston: Academic Press / Morgan Kaufmann. ISBN 0-12-518406-9. Living reference: Severity Ratings for Usability Problems, Nielsen Norman Group, 1994-11-01. Operationalized in references/severity-anchors.md, not as criterion IDs (ADR 0020).","url":"https://www.nngroup.com/articles/how-to-rate-the-severity-of-usability-problems/","accessed":"2026-07-31T00:00:00.000Z","operationalization":"paraphrased"}]
checks	{"scripted":["NNG-H3-DEADEND","NNG-H4-CONTROL-NAMING","NNG-H6-LABELED"],"judged":["NNG-H1","NNG-H2-CONVENTIONS","NNG-H2-LANGUAGE","NNG-H3-EXIT","NNG-H3-UNDO","NNG-H4-EXTERNAL","NNG-H4-INTERNAL","NNG-H5-CONFIRM","NNG-H5-PREVENT","NNG-H6-RECALL","NNG-H7-ACCELERATORS","NNG-H7-CUSTOMIZE","NNG-H8","NNG-H9-IDENTIFY","NNG-H9-RECOVER","NNG-H10-FINDABLE","NNG-H10-TASK-FOCUSED"]}

critique-usability

Critiques an interface design against Nielsen's 10 usability heuristics, operationalized into the 20 NNG-H* criteria in references/NNG-HEURISTICS.md. It reports where a design as specified would obstruct the user: a state with no way out, an action that commits without confirmation, a control nothing on screen names, an error that reports failure without a next step.

Artifact claim

This skill critiques HTML or markdown UI specs, wireframe write-ups, and page mockups. It does not critique live running applications. That narrow claim is deliberate (S-05 (skills slate) AC-8): every criterion here is decided against what the artifact commits to, never against observed runtime behavior. Timing, responsiveness, actual latency, real input handling, and anything that requires operating the interface are out of scope, because a static artifact cannot evidence them and a critique that pretends otherwise is speculation with a criterion ID attached.

What that means in practice:

• A flow whose next state is undefined is a finding about the artifact's silence, reported as such.
• A criterion that would ask how fast something responds instead asks whether the artifact specifies any status indication at all, and whether what it specifies is unambiguous.
• A request to evaluate a deployed URL, a running build, or a recorded session is out of claim. Say so, and critique the spec or mockup if one is supplied alongside it.

Two neighbouring claims belong to sibling skills. Programmatic name, role, contrast, and assistive technology access are critique-accessibility's (WCAG-*). Error and empty-state strings supplied as strings, with no interface around them, are critique-microcopy's (NNG-EM-*). references/NNG-HEURISTICS.md, "Boundaries with sibling skills", draws both lines.

Contract

Every finding this skill emits conforms to contract/critique-contract.schema.json. See docs/reference/critique-contract.md for the field contracts a schema cannot check on its own: location navigable unaided, evidence quoted or measured rather than characterized, violation naming the breach, fix actionable and specific.

Locations in this domain name the screen or state and the element inside it, in the artifact's own vocabulary: the checkout error state, the account settings tab, step 3 of the onboarding wizard. A finding whose location is the whole artifact is not located.

Criteria

The registry is references/NNG-HEURISTICS.md: 20 criteria across the 10 heuristics, each with its operationalization, its operational test, severity 2 and 3 anchors, and its lane. Read it before sweeping; the criterion text there, not this file, is what a finding cites.