Design Rules
Purpose
Guidelines for the /designer command to produce high-quality design specs that reduce plan-review iterations.
Instructions
Step 1: Load at /designer startup
Read this SKILL.md for overview. Supporting files loaded on-demand per phase.
Step 2: Use phase-driven loading
- Phase 3 (PROPOSE) → read [Spec Quality](spec-quality.md) for approach evaluation criteria
- Phase 4 (WRITE SPEC) → read [Design Checklist](design-checklist.md) for self-verification
- Phase 5 (USER GATE) → verify checklist before presenting to user
Spec Quality Criteria
| Criterion | Required | Check | |-----------|----------|-------| | Context describes current state | Yes | Not just "add X" but "currently Y exists, need X because Z" | | Scope has IN and OUT | Yes | OUT items have explicit reasons | | At least 2 approaches compared | Yes | With pros/cons for each | | Selected approach has rationale | Yes | References constraints from requirements | | Key decisions are numbered | Yes | Each has rationale and impact | | Risks have severity and mitigation | Yes | HIGH risks must have concrete mitigation | | Acceptance criteria are verifiable | Yes | Each can be checked as pass/fail |
Anti-Patterns
| Anti-Pattern | Why Bad | Fix | |---|---|---| | "The obvious approach is..." | Skips exploration, may miss better options | Always compare at least 2 | | Spec without OUT scope | Scope creep during planning | Explicitly list what's excluded | | Vague acceptance criteria ("works well") | Can't verify | Make criteria concrete and testable | | No risks identified | Every design has risks | Identify at least 1 per approach | | Copying task description as context | No analysis | Describe current state, not just goal |
Common Issues
Designer skips CLARIFY phase
Cause: Task seems clear. Fix: Even "clear" tasks benefit from scope IN/OUT confirmation. At minimum, confirm scope.
User rejects all approaches
Cause: Missing constraint not captured. Fix: Ask: "What constraint am I missing?" — don't generate more approaches without new information.
References
- [Spec Quality](spec-quality.md) — detailed quality criteria, approach evaluation matrix
- [Design Checklist](design-checklist.md) — phase-by-phase self-verification