authoring-skills
Installation
SKILL.md
Authoring Skills
Skills are folders with a SKILL.md file. The format itself -- YAML
frontmatter plus Markdown instructions, optional scripts/, references/,
assets/ -- is an open, vendor-neutral standard
(agentskills.io/specification),
originally published by Anthropic and now adopted by a growing list of
clients (Claude Code, Claude.ai, Cursor, Windsurf, Codex/ChatGPT, Gemini CLI,
Cline, Roo Code, and more -- see
agentskills.io/clients). Most skills that
fail to port cleanly do so not because the format disagrees, but because the
author leaned on one harness's extensions to that format, or on assumptions
that harness makes about triggering, tool access, or file layout. This skill
is that checklist.