“Customers kept reporting that the MCP server wasn’t working. They’d open mcp.acme.com/mcp in a browser, get a 401 and a raw JSON blob, and file a ticket.”
The fix is content negotiation. If the request is a browser GET with text/html in Accept and no JSON or SSE, serve an HTML page that explains what an MCP server is and how to wire it up. Tickets dropped. The lesson is not technical. The MCP ecosystem shipped a protocol with zero affordances for the humans who will inevitably paste the URL into a browser, and every vendor now has to bolt this on themselves.