What problem does it solve? Turning a raw product idea into a validated, well-scoped plan is hard: founders skip demand validation, builders skip scope discipline, and ideas go straight to code without a written design. This Skill runs a structured office-hours conversation that pressure-tests an idea before any code is written and saves the outcome as a design doc. ## Core Features & Use Cases - Two brainstorming modes: Startup mode applies six forcing questions (demand reality, status quo, narrowest wedge, future-fit); Builder mode uses design-thinking brainstorming for side projects, hackathons, and open source. - Design doc generation: Writes a versioned design document to ~/.gstack/projects/ with problem statement, premises, approaches considered, success criteria, and a distribution plan, with a Supersedes chain across revisions. - Adversarial spec review loop: Dispatches an independent reviewer subagent to score the doc on completeness, consistency, clarity, scope, and feasibility, fixing issues across up to 3 iterations. - Tiered relationship handoff: Tracks session count in a builder profile and recommends the next review skill (/plan-ceo-review, /plan-eng-review, /plan-design-review) via a decision brief. - Use Case: You have an idea for a developer tool and ask "is this worth building?" The skill walks you through demand evidence and wedge definition, writes a design doc, has it adversarially reviewed, then hands you into an engineering plan review. ## Quick Start Ask the agent to run office hours to brainstorm whether your new product idea is worth building.
