This is a much bigger deal than most people realize. If you don't know why, let me explain.
Agents perform "work" right now by calling "tools". These are just pieces of context shoved into the context window saying "if you think you the next thing you should do falls into one of these categories, then respond with this format" — that format is the "tool" a JSONSchema response which a harness then uses to call a function.
MCP, is best thought of as a way to shove more tools and context into your context window (it has a lot of shortcomings imo). The agent then has to pick which tool out of all the available tools it should call. So the more tools you have, the worse it selects the tools.
@threepointone and @KentonVarda have an excellent article (https://t.co/brec28Wsmm) where they introduced the idea of exposing the MCP tools as an SDK, so to call tools and compose them, the AI just does what it is ALREADY good at: write some code.
The question, as always, is where do you run that code safely. Many have proposed sandboxes and containers as a possible solution, but these are hella slow and make the experience untenable.
Thats what makes this announcement SO important, it allows you to run agent-written code in a matter of milliseconds with the explicit execution environment you specify pulled in (like a database, kv store, etc. Cloudflare calls these "bindings" btw).
In practice, this means people can start building MUCH more effective agents that can *do* a lot more, because they can be exposed to more tools.
Anyway, huge deal. Congrats to the CF team.
One of the most important questions for founders is: How do I make sure agents know about my product and service and choose it? All the old tricks won’t work.
People who figure this out will win big