There’s very little actual engineering going in to designing MCP interfaces to actually efficiently work with the way LLM workflows actually operate. Many MCPs offer tools that allow an LLM to retrieve a list of ‘things that exist’ with the expectation the LLM will then pick something out of that list for further action with a different tool. There’s very little evidence that LLMs are actually good at using tools that work like that, and massive lists of ‘things that exist’ eat tokens and context.

Many businesses are rushing to put out something that fits the MCP standard but not taking the time to produce something that lets an LLM achieve things with their tool.

MCPs are the most basic solution possible. Shoving the tool definitions into a vector store and having a subagent search for relevant tools, then another subagent to run the tools would greatly reduce impact on context. I think it’d work in theory, but it’s so annoying to have to do something like this. We’re still in a world where we have some building blocks rather than full fledged toolboxes.

Love how the MCPs mimic the company they represent in that sense.

I discovered the "Layered Tool Pattern" a few days ago which exposes three tools to discover and execute an arbitrary number of service endpoints. https://engineering.block.xyz/blog/build-mcp-tools-like-ogre...

Most UIs currently are unsophisticated and let you turn on or off the tools on server-by-server basis. For some large servers (especially if they act as aggrgeators) this approach isn't going to be desirable and you are going to want to select individual tools to activate, not servers. But that's a UI issue more than a protocol issue.

There other ways to get the data & do the interactions you need.

Eg. give the model your login token/cookies so it can curl the pages and interact with them - or have it log in as you with Playwright MCP.