What problem does it solve? Turning a vague task or requirement into an actionable development plan is error-prone: scope is misjudged, phases lack clear acceptance criteria, and progress gets lost across conversations. This Skill analyzes the project context, classifies task size (small/medium/large), and produces a structured plan document that both the user and the Agent can follow and resume. ## Core Features & Use Cases - Structured Four-Part Plans: Outputs requirement overview (goal, current state, done criteria), phased breakdown with dependencies, per-phase acceptance criteria plus test cases for large tasks, and a progress tracking table. - Task Size Classification: Judges small/medium/large tasks based on project and module scope, adjusting phase granularity accordingly. - Document Update Mode: Updates an existing plan file in place via patch preview instead of regenerating the full plan, preserving structure and annotating new content. - Progress Persistence & Resume: Maintains a status board in the saved Markdown file so a new conversation can resume execution by reading the progress table; supports optional Git commit+push to a configured docs repository. - Use Case: You describe a cross-project feature request; the Skill scans the workspace, classifies it as a large task, and saves a plan file with 6 phases, test cases, and a progress board you can resume from days later. ## Quick Start Ask the Agent to create a structured development plan for your task by saying "auto-plan: help me plan the user permission refactor across the backend and admin frontend".