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

Phase 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

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:

| 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

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

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

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

| 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)

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

References

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