gsd-mvp-phase

To plan an MVP vertical slice, capture a structured user story, validate its scope using SPIDR splitting to check if it needs decomposition, update ROADMAP.md with MVP mode, and then delegate to detailed phase planning.

SPIDR splitting is a validation technique that evaluates user story size across Spike, Paths, Interfaces, Data, and Rules to determine if a phase is too large and should be split into multiple executable phases before planning.

Updating ROADMAP.md for MVP mode requires writing 'Mode: mvp' and reformatting the 'Goal:' section for the target phase, which configures the roadmap for vertical slice planning before delegating to detailed phase execution.

Converting an existing phase into an MVP slice requires a structured 'As a / I want to / So that' user story to lock scope early, meaning you must define and validate the user story format before MVP planning can proceed.

Validating phase scope requires an existing phase with the correct status guards, a structured user story, and a SPIDR splitting decision workflow to determine if the phase boundaries are executable or need decomposition.

MVP phase planning gets stuck because vague goals and oversized user stories create unclear implementation boundaries that delay execution, which is why structured story capture and SPIDR splitting guardrails are applied to lock scope early.