MCP Explained

The opening has 1 paragraph and 5 table entries. One of them is “Not REST”

It’s a little scary that this was considered too dense or complex because the basics were explained in something that could be read in 1 minute. That still wasn’t enough to stop the top HN comment (as I write this) from calling it too dense and giving incorrect information that is immediately refuted by skimming the top part of the article.

Maybe it was written for an AI? :)

Or by an AI? Or both?

From your comment, I expected to be annoyed by a bunch of slop or obscurities.

My guess is the writing did not come straight out of an LLM and was carefully curated.

If I’m wrong I’d love to have the style prompt.

In theory the agents could just natively know how to do this better, to get exactly the composability you want. In fact, you could probably just write a CLI mcp-caller and tell the agent to only call MCPs via that, and boom you're done.

Where MCP does come back into the picture even for coders is a more controlled way to break a sandbox.

What I will also say is it matters less and less. It's the usual bitter lesson. The models are just getting so much better all attempts to optimize everything are a drop in the bucket.

Internally at my startup, I built an interpreter for a subset of Javascript where the agent can compose its tools and MCPs. The cool thing about it is that it can create durable workflows and automations from these same scripts.

"Find the latest prod JIRAs and analyze the related logs"

What do you mean? DeepSeek Flash 1017 is well over 200GB even at 1 bit quantization, how are you running it locally?

MCP has its place. It should not be the default for many use cases, but if you need to expose specific tools in a secure way to agents that are not trusted to run shell commands then MCP is great. Developers need to think beyond their own use cases and consider architecture patterns if they're going to build, not just consume, AI systems.

People make the argument that it doesn't matter for non-programmers. I use Bluebeam (a pdf editor which is standard in the construction industry) daily, and it has an MCP, but a big problem is that if the agent wants to import or export a large amount of data from a document, then it has to regurgitate a bunch of tokens into or out of the MCP. If it were a CLI, then it would just pipe things in and out as it needs.

I ended up just having the agent make a script that wraps the MCP so it can use it as a CLI instead.

It is the same with a wepapp: You could argue you don't neex browser apps if the user just install a software on their computer, but we feel better using the sandboxing environment of your browser.

Be surprised how far apps can get with just solid & well documented APIs. Modern agents are smart!

Their secret, which is not very secret, is to ask the AI to help them set it up.

I think this might follow that bell curve meme where people on the unsophisticated and highly sophisticated ends of the curve are leveraging the LLM for MCP setup (and other routine tasks) while some in the middle are making it more complicated than it needs to be because they still think of it as outside the domain of AI-assisted work.

The biggest problem I see isn’t getting MCP set up, it’s people getting stuck using the wrong tools for the job. I’ve improved a lot of workflows by observing what someone is doing and suggesting a better tool for the job.

Also, Apple just announced their preview for new Siri AI capabilities and part of that is they seemingly are going to add MCP to apps (if developers of the apps want to) as tools, which would enable Siri to use functions of apps, similarly to Claude Desktop using functions of services through MCP tool calls.

At my job we maintain an MCP for our admin portal/prod data and it's seen a lot of use. Our admin side was a mess to use so allowing admins to ask questions about prod data has been a huge help for everyone.

And for myself personally, connecting MCPs to Claude has also been an insanely huge productivity boost. It's really nice to just ask for a link to Datadog when I want to monitor some change I made, instead of trying to craft a query myself.

Just like us to take something and limit it back to being useless until we implement the feature (tools).

The real "race to market" winners will just throw the credentials into the SQL connector and let 'er rip like a real man.

Is it that bad? I have Blender connected to Claude (and my mind is quite blown by how great it is to use) and it was quite easy if you could follow the tutorial (the hardest part was reading that you have to click on something twice)

It was possible without MCP, but arguably this convention made the whole thing a bit more reliable and consistent. It also provides some safe guards against how people might get this data alternatively. People can now ask "What was the ocean acidity like for January 2016 to March 2017 in the Salish Sea? And Claude will reliably draw up a graph for all stations in the Salish Sea monitoring this parameter, report which values have or have not been QC'd, show a map of the stations' locations, etc.

It works better than a skill. It allows me to integrate a protected endpoint more easily for the end users. It only knows about read-only endpoints. No risk of people handing credentials to Claude to make it easier. Overall it makes it pretty seamless to bundle a bunch of domain knowledge into the server, providing access and empowerment to a team of scientists who can but would really prefer not to write API queries when they have one-off questions about our data.

It could also be done with a CLI or something, but, the goal is to provide a powerful interface using simpler tools. An API or CLI would defeat the purpose.

I just don't understand how the whole concept doesn't run afoul of the bitter lesson: agents will figure our tools eventually, they don't need their own.

XML has features that other documents don’t support and thus can be useful in some domains.

Likewise, I find MCP extremely useful for accessing enterprise systems using OAuth. It’s secure, easy to define access controls, and easy to audit.

The same reasons those were needed is why this is needed.

“Claude add an mcp for this”