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Agent Skill

HTML Diagram skill

html-diagramplannotator/effective-htmlskills/html-diagram/SKILL.md

Direct-invocation specialist for self-contained HTML diagrams whose layout, notation, and interaction clarify relationships, sequence, topology, state, hierarchy, or quantitative structure. Use when the user explicitly invokes html-diagram or the broad html skill routes a diagram request here. Do not activate independently from a general request.

3.7kMIT

always on

65 tokname + description

once used

443 tokSKILL.md body

bundled files

11 KB

repo stars

3.7kGitHub

Install the HTML Diagram skill

Skills CLI (Claude Code, Codex, Cursor and others)

npx skills add https://github.com/plannotator/effective-html --skill html-diagram

Claude Code, by hand (all projects)

git clone --depth 1 https://github.com/plannotator/effective-html.git /tmp/effective-html
mkdir -p ~/.claude/skills
cp -R /tmp/effective-html/skills/html-diagram ~/.claude/skills/html-diagram

For one project only, copy the folder into .claude/skills/ in that project instead. The agent picks it up when a task matches its description.

What it costs your context

Agent Skills load in three steps. Tokens counted with the o200k tokenizer; your model's count will differ a little.

WhenWhat loadsCost
Every sessionName and description65 tok
When the agent uses itThe SKILL.md instructions443 tok
Only if opened1 bundled files (1 KB)varies

Until it is used, html-diagram costs about 21× less than the median MCP server we measured (1,363 tokens on every turn). Installing all 7 skills from plannotator/effective-html would load 504 tokens of descriptions. Skills vs MCP study

Checks

Our checks found nothing to flag: it follows the Agent Skills specification's naming and size guidelines and doesn't pipe downloads into a shell.

Checked 2026-10-22 · method

What's inside

The headings of its SKILL.md. Read the full file on GitHub.

  • HTML Diagram
  • Choose the right model
  • Choose the rendering method
  • Build and verify

More skills from plannotator/effective-html

All skills in this repo
  1. big-pics-little-wordsplannotator/effective-html

    Explain the current subject in HTML with large visuals and minimal text while preserving key details.

    3.7k25 tok idle · 81 in use
  2. design-artifactplannotator/effective-html

    Design principles and creative direction for building HTML artifacts — pages, reports, plans, landing pages, demos, decks, and small tools. Use when creating or restyling any visual HTML deliverable and deciding its palette, type pairing, layout, theming, or overall register, or when the output must not look generically AI-generated.

    3.7k72 tok idle · 2,196 in use
  3. htmlplannotator/effective-html

    Create or redesign self-contained single-file HTML artifacts with a visual direction shaped by the user's brief, project, and subject. Use when HTML is the deliverable for a report, explainer, landing page, presentation, tool, mixed artifact, or broad request. This is the collection's only implicit router. Route clear wireframe, prototype, mockup, plan, or diagram requests to the matching direct-invocation specialist when available. Do not use for ordinary application implementation when a standalone HTML file is not the deliverable.

    3.7k107 tok idle · 1,190 in use
  4. html-planplannotator/effective-html

    Direct-invocation specialist for clear, self-contained HTML plans that preserve source material while improving hierarchy, sequence, ownership, dependencies, and reviewability. Use when the user explicitly invokes html-plan or the broad html skill routes a plan request here. Do not activate independently from a general request.

    3.7k61 tok idle · 388 in use
  5. html-prototypeplannotator/effective-html

    Direct-invocation specialist for polished, responsive, self-contained HTML mockups and interactive prototypes grounded in the user's conversation, product context, and design language. Use when the user explicitly invokes html-prototype or the broad html skill routes a mockup or prototype request here. Do not activate independently from a general request. Treat a mockup as a noninteractive fidelity mode within this skill, not as a separate skill.

    3.7k87 tok idle · 1,074 in use
  6. html-wireframeplannotator/effective-html

    Direct-invocation specialist for low-fidelity, self-contained HTML wireframes that test information hierarchy, content, navigation, task flow, and responsive structure before visual design. Use when the user explicitly invokes html-wireframe or the broad html skill routes a wireframe request here. Do not activate independently from a general request. Do not use for polished mockups or production-like interaction; use html-prototype for those.

    3.7k87 tok idle · 844 in use