Which revision of the Model Context Protocol does your server actually negotiate? Pick the one you care about.
Once the transport is right, the remaining problem is that nobody can see what your server does. MCP Showcase turns the same URL into a live playground with documentation for every tool.
The current one, the previous one, or the original.
We run a real initialize handshake against it.
Against the revision you picked, with the transport and tool list alongside.
MCP revisions are dated rather than numbered, and client and server negotiate a shared one during the initialize handshake. Pick the revision you care about and see what your server actually settles on.
Worth saying plainly, because it saves time: negotiation exists precisely so that a client and a server on different revisions can still talk. Most reported "compliance" failures turn out to be transport mismatches — a client trying streamable HTTP against a server that only speaks the older HTTP+SSE transport, which fails whatever revision they would have agreed on.
Check the transport first with the streamable HTTP tester or the SSE tester, then come back here.
Once a client can reach your server, the remaining problem is that nobody can tell what it does. A tool list is not a demonstration, and a prospect will not install a client to find out. MCP Showcase points at the same URL and produces a live playground with generated documentation for every tool, so evaluating your server takes a click.