| name | plan-feature |
| description | Run the three-phase Feature Planner validation before implementing a feature. Use when the user says plan feature, plan a new feature, I want to add, or any request for structured feature planning with edge case and risk analysis. |
Context
- Current branch: !
git branch --show-current
- Recent changes: !
git log --oneline -5
- Project structure: !
ls -la
Your Task
You are invoking the Feature Planner agent workflow. Run all three validation phases for the following feature:
Feature: $ARGUMENTS
Phase 1: Domain & Spec Validation
Before planning, validate the project's documentation and specs:
- Completeness: All key features specced? Features in README but missing from specs?
- Gaps: Missing specs, undocumented decisions, features without tasks
- Consistency: Do specs, README, and tasks tell the same story? Contradictions?
- Staleness: Specs outdated relative to completed work? CHANGELOG accurate?
- Coverage: Tasks cover all specced features? Orphaned tasks?
- Clarity: Requirements precise enough to implement? Vague language?
- Data model: Entities, relationships, invariants defined? Missing fields or constraints?
- API contracts: Endpoints, payloads, error responses, status codes documented?
- Non-functional requirements: Performance targets, scalability, availability, rate limits?
Report each item as PASS / WARN / BLOCK. Stop if any BLOCK items exist.
Phase 2: Task Validation
For each task derived from the feature:
- Requirements clarity: Specific and testable? Flag vague language
- Acceptance criteria: Concrete, verifiable, can each become a test?
- Scope: Too big? Too small? Clear boundaries?
- Edge cases: Error states, empty states, concurrent access, boundary conditions, null inputs, permission denied, timeout/retry, race conditions
- Dependencies: Other tasks, services, APIs, feature flags?
- Security implications: Auth, user data, financial transactions?
- Data implications: Schema changes? Migration? Breaking changes?
- Observability: Logging, metrics, alerting needs?
- Rollback strategy: Safely revertible? Feature flag needed?
- Domain consistency: Aligns with specs and architecture?
Output a refined task definition for each task with all gaps filled.
Phase 3: Implementation Plan Validation
Build and validate the implementation plan:
- Spec-plan alignment: Addresses all requirements and acceptance criteria?
- Technical approach: Simplest that meets requirements?
- Pattern consistency: Follows existing codebase patterns?
- File coverage: All files that need changes identified?
- Implementation order: Right order? Hidden dependencies?
- Testing strategy: Unit, integration, e2e coverage for critical paths?
- Migration strategy: DB migrations? Feature flags? Backwards compatibility?
- Risk areas: Complex integrations, performance, third-party limits?
- Verification plan: How to prove it works?
Final Output
Produce a consolidated Validated Feature Plan with:
- Validation summary (all 3 phases)
- Warnings and accepted risks
- Refined tasks in implementation order
- Full implementation plan with file changes
- Recommended agent assignments
- Open questions needing human decision
Refer to the Feature Planner agent for detailed output formats.
