Doc Coauthoring guides users and agents through a structured, multi-stage workflow for collaborative document creation, technical specs, proposals, and decision docs. The skill acts as an active guide across three core phases including context gathering, section-by-section refinement through brainstorming and curation, and reader testing to catch blind spots. It helps efficiently transfer context, structure content iteratively, and verify that the final document reads clearly for others. Reach for this skill whenever a user is starting a substantial writing task or needs help drafting structured professional documentation.