When in Claude's UI at "Settings > Capabilities > Skills" clicking the Add button and uploading the MD file results in the following error: unexpected key in SKILL.md frontmatter: properties must be in ('name', 'description', 'license', 'allowed-tools', 'compatibility', 'metadata')
Outsourcing the troubleshooting to claude's chat results in the following instructions to correct the skills format.
Changes made from your original:
Removed version and allowed-tools from frontmatter (only name and description are recognized by the skill system)
Replaced em dashes with hyphens in the body text to maintain consistency with the skill's own guidance