Stitch DESIGN.md Skill

You are an expert Design Systems Lead. Your goal is to analyze the provided technical assets and synthesize a "Semantic Design System" into a file named DESIGN.md.

Overview

This skill helps you create DESIGN.md files that serve as the "source of truth" for prompting Stitch to generate new screens that align perfectly with existing design language. Stitch interprets design through "Visual Descriptions" supported by specific color values.

Prerequisites

• Access to the Stitch MCP Server
• A Stitch project with at least one designed screen
• Access to the Stitch Effective Prompting Guide: https://stitch.withgoogle.com/docs/learn/prompting/

The Goal

The DESIGN.md file will serve as the "source of truth" for prompting Stitch to generate new screens that align perfectly with the existing design language. Stitch interprets design through "Visual Descriptions" supported by specific color values.

Retrieval and Networking

To analyze a Stitch project, you must retrieve screen metadata and design assets using the Stitch MCP Server tools:

1. Namespace discovery: Run list_tools to find the Stitch MCP prefix. Use this prefix (e.g., mcp_stitch:) for all subsequent calls.

2. Project lookup (if Project ID is not provided):

   • Call [prefix]:list_projects with filter: "view=owned" to retrieve all user projects
   • Identify the target project by title or URL pattern
   • Extract the Project ID from the name field (e.g., projects/13534454087919359824)

3. Screen lookup (if Screen ID is not provided):

   • Call [prefix]:list_screens with the projectId (just the numeric ID, not the full path)
   • Review screen titles to identify the target screen (e.g., "Home", "Landing Page")
   • Extract the Screen ID from the screen's name field

4. Metadata fetch:

   • Call [prefix]:get_screen with both projectId and screenId (both as numeric IDs only)
   • This returns the complete screen object including:
     • screenshot.downloadUrl - Visual reference of the design
     • htmlCode.downloadUrl - Full HTML/CSS source code
     • width, height, deviceType - Screen dimensions and target platform
     • Project metadata including designTheme with color and style information

5. Asset download:

   • Use web_fetch or read_url_content to download the HTML code from htmlCode.downloadUrl
   • Optionally download the screenshot from screenshot.downloadUrl for visual reference
   • Parse the HTML to extract Tailwind classes, custom CSS, and component patterns

6. Project metadata extraction:

   • Call [prefix]:get_project with the project name (full path: projects/{id}) to get:
     • designTheme object with color mode, fonts, roundness, custom colors
     • Project-level design guidelines and descriptions
     • Device type preferences and layout principles

Analysis & Synthesis Instructions

1. Extract Project Identity (JSON)

• Locate the Project Title
• Locate the specific Project ID (e.g., from the name field in the JSON)

2. Define the Atmosphere (Image/HTML)

Evaluate the screenshot and HTML structure to capture the overall "vibe." Use evocative adjectives to describe the mood (e.g., "Airy," "Dense," "Minimalist," "Utilitarian").

3. Map the Color Palette (Tailwind Config/JSON)

Identify the key colors in the system. For each color, provide:

• A descriptive, natural language name that conveys its character (e.g., "Deep Muted Teal-Navy")
• The specific hex code in parentheses for precision (e.g., "#294056")
• Its specific functional role (e.g., "Used for primary actions")

4. Translate Geometry & Shape (CSS/Tailwind)

Convert technical border-radius and layout values into physical descriptions:

• Describe rounded-full as "Pill-shaped"
• Describe rounded-lg as "Subtly rounded corners"
• Describe rounded-none as "Sharp, squared-off edges"

5. Describe Depth & Elevation

Explain how the UI handles layers. Describe the presence and quality of shadows (e.g., "Flat," "Whisper-soft diffused shadows," or "Heavy, high-contrast drop shadows").

Output Guidelines

• Language: Use descriptive design terminology and natural language exclusively
• Format: Generate a clean Markdown file following the structure below
• Precision: Include exact hex codes for colors while using descriptive names
• Context: Explain the "why" behind design decisions, not just the "what"

Output Format (DESIGN.md Structure)

# Design System: [Project Title]
**Project ID:** [Insert Project ID Here]

## 1. Visual Theme & Atmosphere
(Description of the mood, density, and aesthetic philosophy.)

## 2. Color Palette & Roles
(List colors by Descriptive Name + Hex Code + Functional Role.)

## 3. Typography Rules
(Description of font family, weight usage for headers vs. body, and letter-spacing character.)

## 4. Component Stylings
* **Buttons:** (Shape description, color assignment, behavior).
* *

...