MCP = Mega Context Problem - Matt Carey - YouTube

 # [MCP = Mega Context Problem - Matt Carey](https://www.youtube.com/watch?v=YBYUvGOuotE) **Visibility**: Public **Uploaded by**: [AI Engineer](http://www.youtube.com/@aiDotEngineer) **Uploaded at**: 2026-04-25T10:00:06-07:00 **Published at**: 2026-04-25T10:00:06-07:00 **Length**: 22:41 **Views**: 18554 **Likes**: 430 **Category**: Science & Technology ## Description ``` The best MCP server is the one you didn't have to build. At Cloudflare we have a lot of products. Our REST OpenAPI spec is over 2.3 million tokens. When teams started building MCP servers, they did what everyone does: cherry-picked important endpoints for their product, wrote some tool definitions and shipped a separate service that covered a small fraction of their API. This was driven by a fundamental context limit of the end users' agent. And tools use a bunch of context just to describe themselves. MCP felt like a Mega Context Problem (and a separate service to maintain). I think we got it all wrong. The context limit is not an MCP problem. It's an agent problem. Tools should probably be discovered on demand and clients are coming around to this. But maybe we can also do it on the server? CLIs get this for free, self-discoverable and documented by design. APIs just need a little help. This talk will cover some of the techniques we've been exploring at Cloudflare, such as codemode and tool search, to make complete APIs accessible to agents through MCP. I'll also cover some of the work we are doing with the MCP Typescript SDK to make stateless servers the default. Speaker info: - https://github.com/mattzcarey - https://www.linkedin.com/in/mattzcarey/ - https://x.com/mattzcarey ``` ## Transcript [music] Hello everyone. Welcome. Quiet down. Quiet down. Hi. Awesome. How is everyone? Yeah. Good. [applause] Thanks. Um, want to hear some MCP versus CLI debates? Yeah. Is that why you all came? Anyway, um, hello. My name is Matt. Uh, I work on MCP and agents at Cloudflare. And welcome to my talk. It's all about how we can make every API a tool for agents. APIs exist in the wild. How can we connect them to agents and make them do things? So, I I really love my job because every day I get to decide like uh if an agent looked like this, would he do this or would he do this? And I think it's kind of fun. Um and we often fluctuate between the two of them. Uh someone does something that you think is slightly funny and then six months later, we're all doing it and claiming it was the best thing in the world. So, yeah, it's really good crack. But the main part of the the role, I guess, and like what I end up doing dayto-day is like how do we give agents hands? How do we let them interact with the outside world? And you're probably familiar with something like this. This is tool calling, function calling. Uh it's been around for a while now. The LM writes a function. You execute the function. Bash bash bash. Weather in London is 18 degrees. It's not. It's like 8 and it's freezing. Um sad times. And then from there, we went from uh bundled tools to something like shared tools. Like people made tools in their agents. And you probably this is like all like recent history so everyone's probably aware of this but before MCP we had like uh people would bundle all their tools in their agents and then they would keep them bundled in their agents and then if I was like trying to interact with Gmail or something I would make loads of tools for Gmail bundle them with my agents and that would be it and the next person would have to do exactly the same thing. And then we ended up with this like big explosion of uh MCP and remote MCP about April last year and the service providers were like oh we can we can like uh give everyone MCP tools and then everyone can use the same standardized tools and we just make it once and we provide it as another surface for people to consume our API. Maybe there's a CLI, there's an API, maybe there's like I don't know GraphQL API and there's now MCP as like another surface. But this got a little bit fun because it was okay with like eight tools, but then what happens if you added like a few more or a few more or a few more or a few more or a few more and now you you you're like, I want to give an agent access to our whole API surface and Well, that ain't gonna that ain't going to happen. Why is that not going to happen? You've exploded a context window of the agent. You've like completely annihilated it. This is 1 point something million tokens. And this was the problem that we like came across a few uh well around a year ago now. We were trying to give access to the whole of the Cloudflare API to agents. You put all of the the you try and make naive tools out of every single API endpoint and you fully explode a context window. Our open API spec is 2.3 million tokens into tools that's something like 1.1 million tokens and that's l