Write VS Code Extension Marketplace Page

README.md for a VS Code extension is rendered verbatim as the Marketplace listing. Write it entirely for end users. Zero developer content in this file.

NEVER include: badges, Contributing section, License section, project structure trees, npm/build/test commands, architecture explanations.

Step 1 — Explore the Extension (Explore subagent)

Spawn an Explore subagent. This keeps codebase detail out of your context:

Agent({
  subagent_type: "Explore",
  description: "Explore VS Code extension codebase",
  prompt: "Explore the VS Code extension at [path or current directory]. Return ONLY:
  1. displayName, description, publisher from package.json
  2. All commands from contributes.commands (title + command id for each)
  3. All settings from contributes.configuration.properties (key, type, default, description for each)
  4. Contents of assets/ folder — list every file
  5. Current README.md H2 section headings (headings only, not content)
  6. Whether DEV.md exists
  Do not return raw file contents. Be concise."
})

Step 2 — Research Marketplace Pages (Research subagent)

Spawn a research subagent to fetch reference pages without bringing raw HTML into this context:

Agent({
  description: "Research VS Code Marketplace page patterns",
  prompt: "Fetch 2 of these VS Code Marketplace pages (pick the most relevant to this extension's domain):
  - https://marketplace.visualstudio.com/items?itemName=CodeRabbit.coderabbit-vscode  (AI/code review tool)
  - https://marketplace.visualstudio.com/items?itemName=eamodio.gitlens              (git/source control)
  - https://marketplace.visualstudio.com/items?itemName=usernamehw.errorlens         (code diagnostics/display)
  - https://marketplace.visualstudio.com/items?itemName=hediet.vscode-drawio         (visual/diagram tool)

  For each page, return ONLY these extracted patterns — no raw content:
  1. Hook structure: does it lead with problem or feature? How long is the opening?
  2. Badges: yes/no, which ones?
  3. Feature section: bold-headline+GIF vs bullet list vs prose?
  4. Section order: list the H2 headings in order
  5. Approximate word count
  6. Does it have Contributing or License sections in the body?

  End with: which 2 pages you fetched."
})

Tell the user which 2 pages were referenced.

Step 3 — Plan (confirm before writing)

Show the user a short bullet list of planned README.md sections. Say:

"Here's what I'm planning — let me know if you want to adjust anything, otherwise I'll go ahead."

Step 4 — Write README.md

Hard rules — no exceptions

• No badges — the Marketplace sidebar already shows version, installs, rating, license, publisher
• No Contributing section — goes in DEV.md
• No License section — shown in Marketplace sidebar automatically
• No project structure — developer content
• No npm commands — developer content

Structure

# [displayName]
> One outcome-focused tagline (not a feature list — what does the user GET?)

[Hook: 2–3 sentences. LEAD WITH THE PROBLEM. What frustration does this solve?
Do not start with "Coverage Visualizer is a..." — start with the user's situation.]

![Demo](assets/demo.gif)

---

## Features

**[Feature name]** — one sentence of concrete user benefit.

[GIF or screenshot immediately after its feature, if available]

[Repeat — bold headline + sentence + visual for each major feature]

---

## Supported Formats   (only if the extension handles multiple input formats)

| Format | How to generate |
|--------|----------------|
| ...    | ...            |

No [runtime] required — the extension reads all formats natively.

---

## Installation

Search for **[displayName]** in the Extensions panel (`Cmd+Shift+X` / `Ctrl+Shift+X`) and click Install.

---

## Quick Start

[2–4 numbered steps. Start from zero. End at the "wow" moment. Use code blocks.]

---

## Commands   (only if the extension contributes commands)

| Command | What it does |
|---------|-------------|
| ...     | ...          |

---

## Configuration

| Setting | Default | Description |
|---------|---------|-------------|
[one row per setting from contributes.configuration.properties]

Asset rules

• If assets/demo.gif exists → ![Demo](assets/demo.gif) — use the real path, no placeholder
• If per-feature GIFs exist (e.g. assets/demo-highlights.gif) → place each after its feature
• If no GIFs exist → <!-- demo GIF: record [specific action to show] --> as placeholder
• Paths must be relative — vsce bundles the assets/ folder so relative paths work on the Marketplace

Writing tone

• Active voice, imperative: "Run pytest" not "You can run..."
• Short sentences — this is a product page, not prose
• Every code snippet in a fenced block with language specified
• Target: 300–500 words. Dense with visuals, light on text.

Step 5 — Write DEV.md (if it doesn't exist)

If DEV.md does not exist, offer to create it. DEV.md must contain everything a contributor needs:

• Prerequisites (Node version, VS Code version, npm)
• Clone + install steps
• How to launch the dev host (F5 in VS Code)
• Architecture overview (what each src/ file/folder does)
• All npm commands (compile, watch, test, lint, test:coverage)
• Project structure tree
• How to run a single test
• Fixture regeneration instructions (if applicable)
• PR guidelines (branch naming, test requirements, PR description format)

Step 6 — Deliver

1. Write README.md to the extension root
2. Write DEV.md if it was missing and user agreed
3. Report:
   • Which 2 Marketplace pages were referenced
   • Each GIF placeholder left and exactly what to record
   • Whether DEV.md was written or already existed