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name: prd-writing description: Creates developer-friendly PRDs with dual-format output (human-readable + machine-readable YAML). Use when users want to write a PRD, document feature requirements, create product specs, or turn ideas into structured requirements. Guides through 4 phases - requirement clarification, human sections, AI outline review, and final output. Supports bilingual (English/Chinese) PRD generation.

PRD Writing Skill

Create clear, developer-friendly Product Requirements Documents with dual-format output.

Core Principles

1. Be a thinking partner — Help PMs clarify thoughts, not just transcribe them
2. No redundancy — User perspective and system perspective are different views
3. Right audience — Overview/Metrics for leadership, requirements for developers, YAML for AI
4. Filesystem as memory — Write decisions to file immediately, read before each phase

Workflow Overview

CopyPhase 0: Requirement Clarification
         ↓ CREATE prd-[feature]-clarification.md
         ↓ CREATE prd-[feature].md

Phase 1: Write Human-Readable Sections
         ↓ UPDATE prd-[feature].md

Phase 2: Generate For-AI Outline (PM Review)
         ↓ APPEND outline to prd-[feature].md

Phase 3: Final Output + Bilingual Option
         ↓ UPDATE prd-[feature].md
         ↓ ASK: Generate Chinese version?
         ↓ IF YES: CREATE prd-[feature]-zh.md

File Operations

Critical Rules:

• Create files FIRST, before asking clarification questions
• Update clarification log after EACH decision, not in batches
• Read files before each phase to refresh context
• When updating bilingual PRDs, sync BOTH versions

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Phase 0: Requirement Clarification

Input: PM's raw requirement (bullet points, sentence, or rough document)

FIRST ACTION: Create two files using templates from references/templates.md

Clarification Strategy

Ask about these areas when unclear:

After Each PM Answer

UPDATE Key Decisions table in clarification log immediately:

Copy| Scope | Web or API? | Web only |
| Threshold | How many failures? | 5 in 5 minutes |

When to Escalate

Log in Escalation Notes and suggest PM consult:

• Technical feasibility unclear → Tech Lead
• Complex business rules → Business/operations team
• Compliance/legal concerns → Legal team
• Cross-team dependencies → Other teams first

Phase 0 Complete

When PM confirms requirements are clear:

1. Update Document Status: Clarification → ✅ Complete
2. Proceed to Phase 1

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Phase 1: Write Human-Readable Sections

FIRST: Read both files to refresh context.

Fill in PRD sections. See references/templates.md for detailed section templates.

Section Overview

1. Overview — Feature name, one-sentence summary, business context
2. Success Metrics — Metrics aligned with problem statement
3. Impact Scope — Systems affected (brief list)
4. User Perspective — User stories, happy path, edge cases, UI prototype
5. System Perspective — Architecture, functional requirements, NFRs
6. Other Notes — Dependencies, compliance, assumptions, risks, out of scope

Phase 1 Complete

1. Update Document Status: Human Sections → ✅ Complete
2. Ask PM to review
3. After PM approval, proceed to Phase 2

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Phase 2: Generate For-AI Outline

FIRST: Read both files to refresh context.

APPEND outline to PRD (don't replace For AI section yet). See references/templates.md for outline format.

Outline Contents

1. Entities Identified — Data entities with fields
2. APIs/Interfaces — Endpoints (mark inferred ones)
3. Business Rules — Condition → action pairs
4. Technical Details Added — Defaults you assumed (PM must confirm)
5. Open Questions — Items needing PM clarification

Why This Step Matters

• PM discovers gaps they hadn't considered
• Technical defaults are made explicit
• Unclear areas are surfaced before they become bugs

Phase 2 Complete

1. Update Document Status: For AI Outline → ✅ Complete
2. Wait for PM approval before Phase 3

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Phase 3: Final Output + Bilingual Option

FIRST: Read both files to refresh context.

Step 1: Update Human Sections

Add confirmed details back to human-readable sections:

• Add to Functional Requirements if significant
• Add to Other Notes if supplementary

Step 2: Generate For-AI Section

Replace outline with complete YAML specification. See references/yaml-spec.md for the full YAML schema.

Step 3: Bilingual PRD Generation

After completing the English PRD, ASK the user:

"PRD is complete. Would you like me to generate a Chinese version (prd-[feature]-zh.md)?"

If YES:

1. Create prd-[feature]-zh.md with translated content
2. Keep the same structure and section headers (translated)
3. Preserve technical terms, API names, and code in English
4. Add cross-reference link in both files:
   • English: > **Chinese Version:** [prd-[feature]-zh.md](prd-[feature]-zh.md)
   • Chinese: > **English Version:** [prd-[feature].md](prd-[feature].md)

Bilingual Sync Rules:

• When updating either version, ALWAYS update both
• Before making changes, READ both files
• After changes, verify both files are in sync
• Technical accuracy takes priority over translation elegance

Step 4: Update Document Status

Copy| Phase | Status | Date |
|-------|--------|------|
| Clarification | ✅ Complete | YYYY-MM-DD |
| Human Sections | ✅ Complete | YYYY-MM-DD |
| For AI Outline | ✅ Complete | YYYY-MM-DD |
| Final | ✅ Complete | YYYY-MM-DD |
| Chinese Version | ✅ Complete | YYYY-MM-DD | (if applicable)

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Behavior Rules

DO:

• Create files FIRST, before clarification questions
• Update clarification log after EACH decision
• Read files before each phase
• Challenge vague requirements ("what does 'fast' mean?")
• Mark inferred vs. stated requirements
• Ask about Chinese version after PRD completion
• Sync both language versions on any update

DON'T:

• Write PRD without understanding the requirement
• Rely on memory (read the files!)
• Guess technical details without marking as assumptions
• Repeat same information in multiple sections
• Skip outline review step
• Update one language version without updating the other

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References

• Templates: references/templates.md — File templates and section formats
• YAML Spec: references/yaml-spec.md — Complete For-AI YAML schema