Your SKILL.md Works in Claude Code but Silently Fails in VS Code

Not long ago, I had some issues getting my skills files from Claude Code to work in VS Code. No errors, no warnings. Just didn't see it. Turned out my name field said one thing while the parent directory was calling another. Claude Code doesn't mind this, but VS Code will not load it. Simple problem, but it wasted more time than I'd prefer to admit. The Portability Problem Nobody Talks About Agent Skills (the SKILL.md format from agentskills.io ) are supposed to be write-once, run-anywhere. Claude Code, VS Code/Copilot, OpenAI Codex, Cursor, Roo Code, OpenCode, and others all support the same spec. In practice, each agent has quirks: VS Code requires name to match the parent directory name exactly. Mismatch = silent failure. The skill never loads, and you get zero indication why. This is documented in VS Code's skill docs , but easy to miss. Claude Code accepts fields like model , mode , disable-model-invocation , and hooks in frontmatter. These are Claude-specific extensions. Other ag