MCP Client Evidence Gate

About This Skill

MCP Client Evidence Gate is a living compatibility/evidence skill for MCP builders who need to keep client verification claims current as MCP clients, agent tools, and marketplace expectations change. Use it when you need to verify MCP server discovery behavior before publishing, compare discovery results between clients, or generate structured compatibility receipts that separate actual-client evidence from fixture coverage and NOT_EXECUTED paths. This is subscription-priced because MCP compatibility evidence goes stale. Codex changes. Qwen changes. Client discovery behavior changes. Marketplace expectations change. A one-time static checklist is not enough when the thing being verified keeps moving. This skill helps you: * Validate MCP server discovery before publishing a release. * Compare discovery behavior between supported clients. * Generate local evidence receipts for MCP compatibility claims. * Separate actual-client evidence from fixture/direct-protocol checks. * Prevent documentation overclaims before buyers or users hit a failure. * Keep a repeatable verification gate as MCP client behavior evolves. Verified v0.1 scope: * Codex CLI v0.142.2 stdio discovery evidence. * Qwen Code v0.19.2 stdio discovery evidence. * Fixture/direct-protocol checks. * Explicit NOT_EXECUTED boundaries for untested paths. This is not a universal MCP conformance suite. It does not claim full protocol coverage, OAuth coverage, hidden client behavior, Streamable HTTP actual-client verification, safe-call actual-client verification, or compatibility with untested clients. Best for MCP server authors, agent builders, tool developers, and marketplace sellers who need living compatibility evidence instead of static claims. More provider updates incoming.