Page Decomposition

Analyze content sequences within an EDS section and provide neutral descriptions without assigning block names.

When to Use This Skill

This skill is called by identify-page-structure for EACH section to:

• Identify content sequences within that section
• Provide neutral descriptions (NO block names yet)
• Identify breaking points between sequences
• Enable authoring-focused decisions later

IMPORTANT: This skill analyzes ONE section at a time, not the whole page.

Input Required

From the calling skill (identify-page-structure), you need:

• Section visual description and boundaries
• Screenshot showing the section
• Cleaned HTML content for the section

Related Skills

• page-migration - Top-level orchestrator
• identify-page-structure - Invokes this skill for each section (Step 2b)
• block-inventory - Provides available blocks AFTER decomposition
• content-modeling - Makes authoring decisions AFTER decomposition
• content-driven-development - References section structure in html-structure.md

Key Concepts

EDS Content Hierarchy:

DOCUMENT
├── SECTION (top-level, analyzed by identify-page-structure Step 2a)
│   ├── Content Sequence 1 ← THIS SKILL IDENTIFIES THESE
│   ├── Content Sequence 2 ← THIS SKILL IDENTIFIES THESE
│   └── ...
└── SECTION
    └── Content Sequence 1

What is a "content sequence"? A vertical flow of related content that will eventually become:

• Default content (headings, paragraphs, lists, inline images), OR
• A block (structured, repeating, or interactive component)

Breaking points between sequences:

• Visual/semantic shift in content type
• Change from prose → structured pattern
• Change from one pattern → different pattern

Philosophy:

• Describe WHAT you see, not WHAT it should be
• "Two images side-by-side" not "Columns block"
• "Grid of 8 items with icons" not "Cards block"
• Stay neutral - authoring decisions come later

Decomposition Workflow

Context: identify-page-structure has already identified section boundaries (Step 2a). This skill is invoked FOR ONE SECTION to analyze its internal content sequences.

---

Step 1: Examine the Section

Look at the screenshot and HTML for THIS section only.

What to observe:

• Vertical flow of content from top to bottom
• Where content changes type or pattern
• Visual groupings or breaks

Ignore:

• Other sections (out of scope)
• Section styling (already identified by page-migration)
• Block names (stay neutral)

Output: Mental model of content flow within this section

---

Step 2: Identify Breaking Points

Find where content shifts from one type/pattern to another.

Breaking point indicators:

• Prose text → Structured grid
• Heading/paragraph → Side-by-side images
• One repeating pattern → Different repeating pattern
• Structured content → Prose text

Example within a section:

Content flows top to bottom:
- Large heading
- Paragraph
- Two buttons
[BREAK] ← Visual/semantic shift
- Two images displayed side-by-side

Output: List of breaking points

---

Step 3: Define Content Sequences

Between each breaking point is a content sequence.

For each sequence, describe:

• What elements it contains (heading, paragraph, images, etc.)
• How they're arranged (stacked, side-by-side, in a grid)
• Quantity (one heading, two images, grid of 8 items)

Use neutral language:

• ✅ "Two images displayed side-by-side"
• ❌ "Columns block with two images"
• ✅ "Grid of 8 items, each with icon and short text"
• ❌ "Cards block"
• ✅ "Large centered heading, paragraph, two buttons stacked vertically"
• ❌ "Hero block"

Output: Neutral descriptions for each sequence

---

Step 4: Return Structured Output

Provide content sequences for this section in structured format.

Output format:

{
  sectionNumber: 1,  // From identify-page-structure
  sequences: [
    {
      sequenceNumber: 1,
      description: "Large centered heading, paragraph, two buttons stacked vertically"
    },
    {
      sequenceNumber: 2,
      description: "Two images displayed side-by-side"
    }
  ]
}

This enables:

• Clear understanding of section's internal structure
• Neutral foundation for authoring decisions
• Separation of description from implementation

---

Section Metadata Format

Markdown format:

+------------------------------+
| Section Metadata             |
+------------------+-----------+
| style            | light     |
+------------------+-----------+

Placement: At the start of each section, before content

Usage: Applied by generate-migration-html skill when generating final HTML

---

Examples

Example 1: Hero Section

Input: "Section 1 (light background): Large prominent content at top of page"

Visual observation:

• Large centered heading
• Paragraph text below it
• Two call-to-action buttons [BREAK - visual shift]
• Two large images displayed next to each other

Output:

{
  sectionNumber: 1,
  sequences: [
    {
      sequenceNumber: 1,
      description: "Large centered heading, paragraph, two call-to-action buttons stacked vertically"
    },
    {
      sequenceNumber: 2,
      description: "Two large images displayed side-by-side"
    }
  ]
}

---

Example 2: Features Section

Input: "Section 2 (light background): Grid of feature items"

Visual observation:

• Centered heading [BREAK - shift to structured pattern]
• Grid of 8 items
• Each item has: small icon, short text description [BREAK - shift back to simple elements]
• Two centered buttons

Output:

{
  sectionNumber: 2,
  sequences: [
    {
      sequenceNumber: 1,
      description: "Single centered heading"
    },
    {
      sequenceNumber: 2,
      description: "Grid of 8 items, each with small icon and short text description"
    },
    {
      sequenceNumber: 3,
      description: "Two centered buttons"
    }
  ]
}

---

Example 3: Article Cards Section

Input: "Section 3 (grey background): Blog articles"

Visual observation:

• Eyebrow text "Latest Articles"
• Large heading
• Paragraph description
• Browse button [BREAK - shift to repeating pattern]
• 4 items in grid
• Each item: image, category tag, heading, short description, read link

Output:

{
  sectionNumber: 3,
  sequences: [
    {
      sequenceNumber: 1,
      description: "Eyebrow text, large heading, paragraph description, browse button - all stacked vertically"
    },
    {
      sequenceNumber: 2,
      description: "Grid of 4 items, each with image, category tag, heading, description, and read link"
    }
  ]
}

---

Example 4: Simple Content Section

Input: "Section 4 (light background): Body content"

Visual observation:

• Multiple paragraphs of text
• Some inline images within the text
• Headings interspersed (H2, H3)
• No clear breaking points - content flows naturally

Output:

{
  sectionNumber: 4,
  sequences: [
    {
      sequenceNumber: 1,
      description: "Flowing prose content: multiple paragraphs with inline images and headings (H2, H3)"
    }
  ]
}

Note: This entire section is one sequence because content flows naturally without structural breaks.

---

Common Mistakes to Avoid

Using block names in descriptions: ❌ "Hero block with heading and buttons" ✓ "Large centered heading, paragraph, two buttons stacked vertically"

Not identifying breaking points: ❌ Describing entire section as one sequence when there are clear shifts ✓ Identifying where content type changes and breaking into sequences

Being too granular: ❌ Each element as separate sequence: "Heading", "Paragraph", "Button" ✓ Related elements together: "Heading, paragraph, two buttons stacked vertically"

Mixing analysis levels: ❌ Analyzing multiple sections at once ✓ Focus on ONE section at a time (per invocation)

Making authoring decisions: ❌ "This should be a cards block because..." ✓ "Grid of 4 items with images and text" (neutral description)