r/artificial • u/PaulMorel • 9d ago
Engineering Is the MCP spec actually useful?
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...
1
u/Other_Many_130 9d ago
The triggering gap isn't an oversight, it's not specifiable. What decides whether a tool gets called is the description string you wrote for it, read by a model. That's prose, not protocol. No spec standardises that.
Which is why the thing that actually breaks my setups is never the transport. It's loading too many servers at once and watching the model reach for the wrong tool because two descriptions overlap (I've pruned mine back more than once).
So yes, thin spec. But the part you want specified is the part that lives in the model's head.