MCP pagination empty nextCursor handling looks like a tiny null check, but the wrong predicate can hide most of a server's catalog. In the final 2026-07-28 specification, cursors are opaque strings. An empty string is valid; only a missing nextCursor ends traversal. In a nullable C# response model, that absence is represented by null . I built a small .NET 10 verifier because this failure is unusually quiet: the request succeeds, the first page looks reasonable, and no error says that later...