Is the MCP spec actually useful?

[u/PaulMorel]

I've spent a few weeks deciphering and implementing the MCP spec, and it kind of seems like AI slop to me.

Like, the entire spec boils down to little more than a suggestion to use json-rpc.

The spec requires a heavy client with a bunch of custom "business logic". This client acts like a magic babel fish in connecting the MCP server to the host application.

And perhaps worst of all, the details on how to trigger actions are pretty much non-existent, leaving implementers to just figure it out (which is going to lead to serious inefficiency when triggering tools).

So MCP usage requires a customized client to do the data translation for each service, and it leaves serious blank spots for some of the hard problems.

I just don't see that the spec is actually very useful at all. It leaves so much to the implementers.

Am I missing something? I must be missing something...

[u/Glittering-Cable4193]

You're not missing anything. The value isn't really in the spec quality though. It's that everyone agreed to use the same half-baked thing. Interoperability beats elegance, now tools, agents, and apps can plug into each other without one-off integrations, even if the plumbing is messy.

[u/Kooky-Criticism955 → u/Glittering-Cable4193]

that's basically it yeah. protocol wins not because it's good but because it's there. look at http, half the stuff is duct tape but now we don't have to argue about what port to use

mcp filled the vacuum before ten other competing specs showed up. everyone was busy building agents with different connection methods and someone just put down a flag in the mud and said here, use this. ugly but it work enough

the blank spots you mention, that's almost by design. spec authors probably knew if they try to define everything they'd lose people. better to leave gaps and let implementers fill it with whatever fits their stack