Conciseness

The body is skill-specific with essentially no general-concept padding (all content concerns window.Magic APIs, tiptap mention JSON, manifests, file-naming rules), but there is noticeable duplication: the full ~40-line tiptap @file mention JSON block appears essentially verbatim four times (Runtime Trigger example, @skill invocation example, Pattern 1, Pattern 2), and rules like "default to the first available model", "provide agent selector + model selector UI", and the getAppBasePath/basePath prefixing rule are each restated in 3+ sections. Not 4: the repeated large code blocks are more than "minor instances" of over-explanation; not 2: nothing explains concepts Claude already knows, so it is above "several unnecessary explanations or padded sections".

Actionability

Quotes: complete executable artifacts — the app.json template ("type: 'micro-app'... entry: 'index.html'"), the magic.project.js JSONP template, copy-paste-ready createTopicAndSend calls with full tiptap JSON mention structures, the initAgentSelector/getSelectedAgentId functions, concrete CLI usage ("python agents/skills/html-app-architect/scripts/list_agents.py --name-filter 'Data'"), and precisely specified helpers with byte limits ("buildRecordFileName... keep the full file name under 120 UTF-8 bytes, titleSlug under 40 bytes"). These cover the common Simple/Medium/Complex cases. Not 4: the only unimplemented snippets (waitForFile, getSelectedModel) are trivially understood helpers, and the genuinely hard parts (mention JSON structure, manifests) are fully spelled out.

Workflow Clarity

Quotes: the six-phase Core Workflow with an explicit gate — "⭐ Design Review (output to user for confirmation)... Wait for user confirmation before proceeding"; a clarification loop — "If user requests changes during review, update the design and re-confirm"; and validation steps — "Validate with quick_validate.py (for companion skills)", "Validate that the file is well-formed SVG and contains no active content before writing app.json", "If generation or validation fails, report the failure; do not reference a missing file—omit the icon field instead", plus ask_user criteria and the rename-collision check ("call listDir() and reject if the target name exists with a different shortId"). Not 4: validation checkpoints are explicit and paired with error-recovery feedback loops, which is the level-5 anchor.

Progressive Disclosure

Quotes: "How to Use This Document" routes readers ("Any task using window.Magic.* APIs → load this skill first, then use read_skills(['html-api-sdk'])"), and the Reference Documents section gives one-level-deep links with when-to-read triggers ("Before writing any HTML → always call read_skills(['html-api-sdk'])", "When detecting legacy .magic/<name>/SKILL.md paths → read legacy-migration.md") — all three referenced files (skill-generation-patterns.md, app-architecture-patterns.md, legacy-migration.md) exist in references/. Not 5: references/model-info-schema.md is present in the bundle but never referenced or discoverable from SKILL.md, and the list_agents.py command uses an install-time path (agents/skills/html-app-architect/scripts/list_agents.py) that does not match the bundle-relative scripts/list_agents.py. Not 3: references are clearly signaled with explicit load triggers and the API bulk is correctly offloaded to html-api-sdk rather than inlined.

Specificity

Quotes: "building or modifying an interactive HTML app... including pages, tools, forms, dashboards, CRUD interfaces, data visualizations, and window.Magic API integrations" plus "architecture, file persistence, Agent dispatch, and UI decisions" — multiple specific concrete actions with comprehensive coverage of the skill's domain. Not 4: within its stated scope the capability list has no noticeable gaps; not below 5 because every named action is concrete rather than generic.

Completeness

Quotes: what — "building or modifying an interactive HTML app... architecture, file persistence, Agent dispatch, and UI decisions"; when — "Use FIRST for building or modifying an interactive HTML app in an ordinary project context", reinforced with explicit negative triggers ("Do not use it for the built-in published micro-app development flow", "Skip read-only documents..."). Both what and when are explicit with concrete trigger phrasing. Not 4: the when-clause is explicit and specific rather than merely present-but-could-be-tighter.

Trigger Term Quality

Quotes: "HTML app", "forms", "dashboards", "CRUD interfaces", "data visualizations" — natural phrases a user would say. Not 5: common variations such as "web app", "web page", "frontend", or a file extension like ".html" are absent. Not 3: coverage goes well beyond one or two generic keywords and includes several natural user-facing terms.

Distinctiveness Conflict Risk

Quotes: "Do not use it for the built-in published micro-app development flow; use micro-app-architect for that scenario", "calendar projects handled by magic-calendar", "For projects that need a package manager, a build toolchain, or a backend service, use vibe-coding" — sibling-skill conflicts are disambiguated head-on, and the platform-specific "window.Magic API integrations" marker carves a clear niche. Not 4: overlap risk is actively resolved by routing rules rather than merely minor.