MCP has "MCPs" - The Model Context Protocol has Many Critical Problems

⚠️ MCP has "MCPs" - The Model Context Protocol has Many Critical Problems ⚠️

Momentum of Anthropic's Model Context Protocol (MCP) has been accelerating faster than a Falcon 9 rocket. But as we at ACI.dev shipped the world's first Unified MCP server, we noticed serious technical limitations. Note: Many points here might be addressed by features on the roadmap, but that does not detract from its flaws.

🧸 MCP Is Casual

• 👶🏻 MCP was clearly designed for individual developers, not businesses. The architecture makes a fundamental assumption of single-user scenarios, with no multi-tenant capabilities.
• 🤡 Authentication is a circus. Each server implements its own authentication scheme (or none at all), creating a fragmented ecosystem. Clients like Cursor don't support passing auth tokens to servers (as of 26th Mar), so authenticated servers won't even work with these clients.

🤕 DX Headaches

• Debugging is a nightmare. You're juggling MCP Inspector, Chrome DevTools, and digging through log files. (RIP to "print" debuggers like me when building stdio MCP Servers)
• 👀 Tool discovery is basic. The list_tools() endpoint gives you basic pagination with zero filtering and searching capabilities. And server developers have to implement their own pagination logic.
• 💥 Name collisions are your problem. If you integrate multiple MCP servers you'll need to manually handle tool name collisions. (This may be addressed by Anthropic's future MCP registry)

🧩 Ecosystem Fragmentation

• 🦀 Everyone's reinventing the same wheels. Developers are building the same API connectors, file system access, and database integrations with inconsistent quality.
• ⛓️‍💥 "Decoupled" is a myth. Server developers are forced to build for the lowest common denominator of client capabilities (Cursor, Windsurf, etc). If a client doesn't support your authentication method (or protocol type), your server is effectively unusable for a major segment of users.

Protocol Problems

• 🥴 Stdio and SSE. Using stdio means servers must run locally, creating major deployment and usage limitations. The mix of SSE and HTTP POST in this architecture is awkward at best. They're promising streamable HTTP in the future, but curious why they did not go with that in the first place.

🧨 Complexity Timebomb

• New features will bloat server design. Each new feature on the roadmap (OAuth, discovery, remote MCP support) will complicate server implementation, contradicting MCP's promise of simplicity. Supporting other function schema (OpenAI etc) will further increase your complexity.
• 💡 Most users just need tool calling, which could be implemented through a much simpler, specialized platform like ACI.dev without all this overhead.

What are your experiences with MCP? Have you run into these issues? Why do you believe in MCP? Drop your thoughts in the comments.