PRD Analysis Skill
This skill provides structured knowledge for analyzing existing Product Requirements Documents to identify quality issues and guide resolution.
Analysis Philosophy
Depth-Aware Analysis
PRD analysis must respect the intended depth level of the document. A high-level PRD should not be flagged for missing API specifications, just as a full-tech PRD should be scrutinized for technical completeness.
Key Principle: Only flag what's expected at the document's depth level.
Constructive Approach
Findings should be:
- Actionable: Clear recommendation for how to fix
- Specific: Exact location and description of issue
- Prioritized: Severity indicates importance
- Helpful: Explain why this matters, not just what's wrong
Systematic Coverage
Analysis covers four distinct categories to ensure comprehensive review:
- Inconsistencies: Internal contradictions or mismatches
- Missing Information: Expected content that's absent
- Ambiguities: Unclear or vague statements
- Structure Issues: Formatting, organization, missing sections
Finding Categories
1. Inconsistencies
Issues where the PRD contradicts itself or uses conflicting information.
What to Look For:
- Feature named differently in different sections
- Priority mismatches (feature marked P2 but in Phase 1)
- Metrics that don't align with stated goals
- Contradictory requirements
- Timeline/phase misalignment
Detection Strategy:
- Build glossary of feature names from first mention
- Track priority assignments
- Map goals to metrics
- Compare requirements for conflicts
2. Missing Information
Expected content that is absent based on the PRD's depth level.
What to Look For:
- Required sections for depth level
- Undefined technical terms
- Features without acceptance criteria (detailed/full-tech)
- Error scenarios not addressed
- Dependencies not listed
- Incomplete personas
Detection Strategy:
- Compare against depth-level checklist
- Identify domain terms without definitions
- Check each feature for expected attributes
- Scan for external system references
3. Ambiguities
Statements that are unclear or could be interpreted multiple ways.
What to Look For:
- Vague quantifiers ("fast", "many", "scalable")
- Undefined priority language ("should" vs "must")
- Ambiguous pronouns ("it", "this", "they")
- Open-ended lists ("etc.", "and more")
- Undefined scope boundaries
Detection Strategy:
- Flag quantifiers without numbers
- Check for RFC 2119 language consistency
- Identify pronouns with unclear antecedents
- Find incomplete enumerations
4. Structure Issues
Problems with document organization, formatting, or references.
What to Look For:
- Missing required sections
- Content in wrong section
- Inconsistent formatting
- Orphaned references
- Circular dependencies
Detection Strategy:
- Verify all template sections exist
- Check content placement logic
- Validate formatting consistency
- Test all internal references
Severity Levels
Critical
Definition: Issues that would cause implementation to fail or go significantly wrong.
Assign When:
- Fundamental contradiction in requirements
- Core requirement completely undefined
- Required section missing entirely
- Circular dependencies that block implementation
- Security requirement absent (when security is mentioned)
Examples:
- "User authentication required" but no auth requirements defined
- Feature A depends on Feature B, Feature B depends on Feature A
- Full-tech PRD with no API specifications
Warning
Definition: Issues that could cause confusion or implementation problems.
Assign When:
- Inconsistent naming that could cause misunderstanding
- Acceptance criteria too vague to test
- Important feature lacks error handling
- Ambiguous language for significant functionality
- Minor dependencies unlisted
Examples:
- "Search should be fast" without defining "fast"
- User story without acceptance criteria
- Integration mentioned but not in dependencies
Suggestion
Definition: Improvements that would enhance PRD quality but aren't blocking.
Assign When:
- Style or clarity improvements
- Non-critical sections could be clearer
- Best practices not followed
- Minor formatting inconsistencies
- Documentation enhancements
Examples:
- User stories formatted inconsistently
- Glossary would help but isn't critical
- Additional context would be helpful
Analysis Workflow
Step 1: Read and Detect Depth
- Read the entire PRD
- Detect depth level using indicators (see
references/analysis-criteria.md)
- Note the detected depth for criteria selection
Step 2: Load Criteria
Load the appropriate checklist from references/analysis-criteria.md based on detected depth level.
Step 3: Systematic Scan
Analyze the PRD section by section:
- Structure Scan: Verify all required sections exist
- Consistency Scan: Build glossary, track priorities, map goals to metrics
- Completeness Scan: Check each feature for expected attributes
- Clarity Scan: Flag vague language and ambiguities
Step 4: Categorize and Prioritize
For each finding:
- Assign to one of four categories
- Determine severity based on impact
- Identify specific location (section, line)
- Draft recommendation
Step 5: Generate Report
Create report using references/report-template.md:
- Fill in header information
- Calculate summary statistics
- List findings by severity
- Write overall assessment
Update Mode Workflow
When entering update mode for interactive resolution:
Finding Presentation
Present each finding with:
FINDING X/Y (N resolved, M skipped)
Category: {category}
Severity: {severity}
Location: {section, line}
CURRENT:
{Quoted text from PRD}
ISSUE:
{Clear explanation of the problem}
PROPOSED:
{Suggested fix text}
[Apply] [Modify] [Skip]
User Response Handling
Apply:
- Use Edit tool to apply the proposed change
- Mark finding as "Resolved" in report
- Increment resolved counter
- Move to next finding
Modify:
- Ask user for their preferred text via AskUserQuestion
- Apply their modified version
- Mark finding as "Resolved"
- Move to next finding
Skip:
- Ask if they want to provide a reason (optional)
- Mark finding as "Skipped" with reason if provided
- Increment skipped counter
- Move to next finding
Session Completion
After all findings processed:
- Update report with Resolution Summary
- Show final statistics
- List resolved and skipped findings
- Provide recommendations for future PRDs
Reference Files
references/analysis-criteria.md - Depth-specific checklists and detection algorithms
references/report-template.md - Standard report format
references/common-issues.md - Issue pattern library with examples