Specify Skill

Purpose

Core principle: Understand before specifying. No spec without exploring the problem space first.

Create or update specs/{feature}/spec.md from user requirements. Resolve ambiguity within this skill before handing off to downstream phases.

Input

• User requirements
• Existing specs/constitution.md when present
• Existing specs/{feature}/spec.md when present

Output

• specs/{feature}/spec.md

Steps

1. Resolve language and shared rules from specs/constitution.md when present; otherwise infer from the available workflow documents and the user's own message. Ask only if still unclear, then conduct all subsequent interaction in this language.
2. Decide the feature slug and target specs/{feature}/.
3. Create the spec from references/spec-template.md.
   • Keep the spec focused on user needs, behavior, business rules, and constraints
   • Design for isolation and clarity — break the system into units that each have one clear purpose, communicate through well-defined interfaces, and can be understood and tested independently
   • YAGNI ruthlessly — remove unnecessary features from all designs
   • When meaningful alternatives exist, compare 2-3 approaches with trade-offs and record the selected direction plus rejected alternatives concisely
   • Avoid locking in technical design choices unless the user explicitly requires them
   • If optional or secondary capabilities can stand alone, prefer splitting them into separate specs instead of expanding the current one
   • Record spec-to-spec prerequisites only in frontmatter dependencies as specs/{feature}/spec.md paths
   • Write acceptance scenarios as natural sentences that still make context, action, and outcome explicit; avoid forcing literal Given/When/Then wording when it hurts readability
4. Run a specification self-review: Scope, Data, UX, Non-Functional, Integration, Edge, Terminology, Ambiguity, Completion.
5. Ask only high-impact clarification questions.
   • Ask one question at a time
   • Prefer multiple choice when possible — easier to answer than open-ended
   • Actively look for ambiguity that would materially change scope, behavior, data, UX, or downstream execution design
   • If the request describes multiple independent subsystems, stop and surface the decomposition decision immediately — do not spend clarification cycles refining details of a project that first needs to be split into separate specs
   • Resolve high-impact ambiguity before recommending the next phase
   • Delegate low-impact open points to spec-research for investigation
6. Integrate answers directly into the spec.
7. Update frontmatter.
   • Required keys: status, summary, dependencies
   • Initial status: draft
   • Set dependencies: [] when the spec has no prerequisite specs
   • Set status: approved when no unresolved high-impact ambiguity remains and the spec is ready for execution design and tasking
8. Perform final review and keep the file within 150 lines.
   • Remove repetition, simplify wording, resolve contradictions
9. In the completion message, suggest the next step.
   • If review-ready: spec-plan
   • If open points need investigation: spec-research
   • If more refinement is needed: continue spec-specify

Success Criteria

• Prioritized user stories include at least one P1 story.
• Acceptance scenarios are testable.
• Functional requirements align with success criteria.
• Material alternatives and the selected direction are explicit when they affect scope.
• No unresolved high-impact ambiguity remains before handoff.

Completion Guidance

• Next recommended step: spec-plan (or spec-research if open points remain)
• Include the target feature and generated spec.md path in the response