This popped out of my agent: claude plugin validate is unavailable because claude is not on PATH;

I am running ---tool copilot

This was the offending line in AGENTS.md: Install commands are copied verbatim from .agents/install-block.md. .claude-plugin/marketplace.json makes the repo its own single-plugin marketplace — a fallback the install block explains, not the documented route. Run claude plugin validate . --strict after touching either manifest. Why a Claude plugin but not (yet) a Codex one lives in .agents/adr/0002-ship-as-a-claude-code-plugin.md.