Skeleton of Thought (SoT)

Generates structure before content—outline first, then parallel expansion.

MUST Invoke When

• Planning implementation of a feature
• User asks for a "plan", "outline", or "roadmap"
• Creating multi-section documents or responses
• Structuring complex output before writing
• Breaking work into phases or components

Output Commitment

This skill produces visible structured output:

• Phase 1: Skeleton only (major sections, no details)
• Phase 2: Expansion of each skeleton point
• Clear separation between structure and content

Do NOT jump to implementation—invoke this skill to show skeleton first.

Core Mechanism

Two distinct phases:

1. Skeleton phase: Generate only the high-level structure (headers, key points, sequence)
2. Expansion phase: Flesh out each skeleton point independently

Process

Phase 1 - Skeleton:
1. Identify the major components/sections needed
2. Determine logical ordering and dependencies
3. Output ONLY the skeleton (no details yet)
4. Validate: Does this structure cover the full scope?

Phase 2 - Expansion:
1. Take each skeleton point in order
2. Expand with full detail
3. Maintain coherence with adjacent sections
4. Check: Does expansion stay true to skeleton's intent?

Key Principles

• Separation of concerns: Structure and content are distinct cognitive tasks
• Parallelization potential: Skeleton points can be expanded concurrently
• Drift prevention: Skeleton constrains expansion, preventing tangents
• Dependency visibility: Structure reveals what must come before what

When to Apply

• Implementation planning (see full scope before diving in)
• Document/report creation
• Presentations and structured communication
• Any multi-part output where order matters
• Complex responses that need organization

Skeleton Pattern

Phase 1 - Generate skeleton only:

For [TASK], create a skeleton outline:
- Major sections/components only
- One line per item (no elaboration)
- Include sequencing/dependencies
- Do NOT expand yet

[Generate skeleton]

---

Phase 2 - Expand sequentially:

Now expand each skeleton point:
- Full detail for this section only
- Stay within the skeleton's scope
- Note dependencies on prior sections
- [Process in dependency order]

Planning Application

Skeleton:
1. Database schema changes
2. API endpoint modifications  
3. Frontend component updates
4. Integration tests
5. Migration script

Expansion (each becomes detailed task list with acceptance criteria)

Anti-Patterns

• Expanding during skeleton phase (defeats the purpose)
• Skeleton too detailed (it's not a full outline, just structure)
• Skeleton too vague (should still capture all major components)
• Ignoring dependencies during expansion
• Not validating skeleton covers full scope before expanding