Product Spec Skill

Use this skill to plan a product: turn an idea (or existing docs) into product-level specs and execution-planning artifacts. This skill does not implement product code.

Philosophy

• Plan right or build twice: one core problem, one primary user, measurable success, explicit MVP scope.
• UX clarity before build: ambiguous UX creates rework and unstable delivery.
• Single source of truth: this skill is the canonical home for PRD/UX/API/architecture/test-plan planning modes.
• Decision quality over length: include only sections that change decisions.
• Fail fast on weak evidence: call out Evidence gap: explicitly instead of inventing facts.

Standards snapshot (March 2026)

• Prefer repo truth, current docs, and cited evidence over generic planning templates.
• Keep outputs implementation-ready: named owners, success metrics, validation gates, and explicit non-goals.
• Use concise clarifying questions, then move quickly into concrete artifacts.
• Default to Mermaid for architecture or flow diagrams when diagrams materially improve decision quality.
• For agent-facing products, specify the robot-mode interface explicitly: machine-readable default, explicit human mode, no-arg quick start, intent-mapped command taxonomy, and deterministic error handling.