The skill describes three stages. First it asks what kind of document it is, who reads it, and what should be different afterward, then collects a dump of context. Second it builds the doc by section. Third it suggests testing the draft in a fresh chat that does not have the original conversation, to see what a new reader misses.
The SKILL.md file has no license line, and there is no LICENSE.txt in that folder. This directory does not label it Apache. Anthropic's repo README says many skills are Apache 2.0, but this folder does not say so itself.