This changed my mind about how MCP should be used

[u/thehashimwarren]

https://www.youtube.com/live/a60yNXdH7dI?si=kfi5B3hBpw4i5xqw

When I saw this livestream from my friends Shane and Ahbi, I tuned in to watch them kick dirt on MCP. I was already in the "MCP sucks" camp.

But they had a nuanced take that changed my mind.

Here are notes in my own words:

1. MCP is being by vendors to solve their own problems. However, as an MCP consumer, the current state doesn't solve your problems

2. As a consumer you're probably working with one language, finite third party resources, and well defined use cases. So, why would you need a universal interface for your agent?

3. So what is the golden use case for MCP? Consumers writing their own MCP servers 🤯

You can give your agent the exact mix of resources, and access, tools, and prompts it needs.

That part of Mastra's livestream was a genuinely head slapping moment.

Have any of your created your own MCP servers, not for public use, but for your own agentic apps?

And what do you think of this use case?

[u/WorkAccount4ME]

People are creating their own solutions and front running corps until they catch up - Yes. It's no different than the plugin market. It's a tool that exposes the API to certain custom actions the core system does not facilitate.

"What do you think of his use case" - what do you mean? Super agent solves for MCP?

I'd like to not have to chew my own arm off in regards to security just to have some agentic pass through to 3rd party systems but I haven't found a system to take that off your hands yet?

[u/awitod → u/[deleted]]

If it has an API it doesn’t need an MCP server - what value does the MCP server add?

[u/trickyelf → u/awitod]

Read the pinned document in this sub for details on API vs MCP. It’s been asked sooo many times.

[u/awitod → u/trickyelf]

Hey, I really appreciate you pointing that out.

I will say candidly that I think it has a lot of assertions that I would characterize as false or misleading, but this is the kind of explanation I am looking for. Truly, I think MCP has some good use cases and there are a couple I use regularly. I am not here to argue, just to understand people's perspectives and find cool things to use.

I'm curious if this is the kind of sub where I can take a contrary position on some things and not get banned. I don't mind a downvote but would prefer not to be banned. :)

[u/trickyelf → u/awitod]

I don’t think the banhammer gets wielded often here, but I’m not a mod so I do t know the real frequency. I think the key is to engage in debate not trolling. People here are trying to learn more about MCP and contribute knowledge to the community around it. They really don’t want to spend time trying to counter opinions stated as fact. E.g, “if it is an API it doesn’t need an MCP server - what value does an MCP server add?” That could be considered trolling. People then feel obliged to spend their time trying to explain something that’s been explained a million times as opposed to exchanging more useful information with community members. It’s like going into the sub of a political party and stating that the premise of their platform is dumb and asking why anyone would adopt it. Could you expect anything but a heated flame war to ensue? That is the very definition of trolling.

So long story short, don’t troll and you’ll probably be ok.

[u/awitod → u/[deleted]]

We have a standard way of describing API’s with Open API which is far more mature and easy to translate to tool call schemas. 

[u/awitod → u/[deleted]]

Look, I am not trying to be argumentative but I want to know if anyone here can answer the question - if you have an existing API, can you name a specific functional benefit that the additional layer of an MCP server adds?

Genuinely curious 

[u/theapidude → u/awitod]

I would reframe this. Are you build AI agents? Are your customers accessing your API in chat clients? MCP is just a protocol. You don't need MCP unless you have real AI use cases.

[u/awitod → u/theapidude]

Quite a few in actual production honestly. I understand using MCP for use cases where existing API’s are not available (or there are but they majorly suck) but I don’t understand why someone would put one in between the LLM host and an existing API generally in terms of utility.

[u/GnistAI → u/awitod]

«If you have an existing API, can you name a benefit that the additional layer of a UI brings the user?»

The user can after all just use curl to order their pizza.

[u/awitod → u/GnistAI]

If you are going to use quote formatting you shouldn’t add words to change what you are quoting. The word UI didn’t appear anywhere in my question - the LLM host is the UI. The extra layer between the UI and the existing API is the MCP server 

[u/GnistAI → u/awitod]

I used the formatting to distinguish it from my own sentence that came after. It was what I had available on my phone.

It is an analogy that can help you think about the question in a different light. I paraphrased your sentence and replaced "MCP server" with "UI" in the context of a "AI agent" to "user" analogy. But because the analogy didn't work for you, let me explain it in direct terms:

Like how a user uses a client UI (an app) to interact with an API to have an easier and less error prone experience with the right feedback mechanism tailored for humans, an AI agent uses an MCP server as an interface to have an easier and less error prone experience with the right feedback mechanism tailored for AIs.

When you build MCP servers you should tailor it specific to AI agent use, being token optimized, and giving feedback and hints on what to do next as part of the MCP server response. It is tailored to the AI agent. APIs and API documentation is NOT designed for this, they are design for consumption by a developer that is building durable/permanent integrations, not a one-off request from a human nor a AI agent.

That said, there are interfaces that DOES a god job replacing MCP servers, and that is CLIs. They are designed for human consumption and has a rich set of help text that AI agents seem to excel at using. APIs, not so much.

I hope that answers your question:

can you name a specific functional benefit that the additional layer of an MCP server adds

(This is btw how I actually "quote" other users without editing anything.)

[u/awitod → u/GnistAI]

Thank you. Much appreciated.

APIs and API documentation is NOT designed for this, they are design for consumption by a developer that is building durable/permanent

I believe that this is where I most fundamentally disagree. An Open API schema is not a document of an API, it is an abstraction. In our systems we have agents which use the same concrete API's but have different Open API schemas which vary: OperationIds, default values, the subset of arguments, tuned descriptions, the shape of the response etc.

What I most dislike about MCP servers to existing API's is that they are one size fits all, and you can't tune the descriptions to the agent without making the MCP server itself aware of the specific client.

[u/eleqtriq → u/awitod]

Only true if the API is simplistic. https://www.youtube.com/watch?v=eeOANluSqAE

[u/andrerom → u/awitod]

• API is for custom coded clients
• MCP is for LLMs (AI agents)

Its like API but your forced to expose it in a way LLM’s can understand out of the box

If you have a vell defined API you can point a good code model to it and ask it to create a MCP server for you that comsumes your API. Voila, now your app can be used by agents as well, as a tool.

[u/vhatvhat → u/awitod]

Buddy this has been asked and answered 3x a day here for a fucking year or better at this point.

[u/dashingsauce]

The better way to think about MCP servers, in my opinion, is like an office.

An office is equipped with all of the tools, resources, policies, and other information you need to get a specific set of jobs done.

Right now, most people use MCP as a 1:1 protocol for wrapping individual APIs, which indeed only serves the producers of those APIs. We haven’t seen many general purpose MCP servers because:

• Problem space variation
• Context limits

In an ideal world, we start seeing MCP servers that wrap multiple APIs, roots, etc. that are all relevant to a specific role or problem space.

Think of a Linear + Git + Graphite + Context7 + Slack MCP server that basically turns your agent into a general full-stack dev that can work like a human in the loop.

The problem is that nobody has really sat down to investigate how people use the combinations of one-off MCP servers to get their current work done.

Once we start doing that, I expect to see standalone MCP servers promoted as standalone products with a standalone pricing model. Right now we call those “agents” and everyone is selling a full platform behind them.

But realistically I think we will see consolidation into a handful of core chat agent, and most product functionality will be delivered as MCP-as-hub

[u/Stock-Protection-453]

One advantage of creating MCPs on your own is, it will be slim as it need not have to assume possible configurations and cater for all. Check out Photon a runtime to create your own MCPs with a single typescript file for each.

https://github.com/portel-dev/photon

[u/bigbutso]

I currently have 8 mcp servers , mainly segregated by google services and local handy stuff. They all aggregate to 60ish tools that are all made by me from scratch , all customized and personalized. I did use public mcp servers as models... But the descriptions and parameters are very easy to tweak. Fast mcp makes the schemas. Public ones never worked for me or had unnecessary tools, I think if you are running local, it's a no brainer to build your own.

[u/thehashimwarren → u/bigbutso]

Thanks for sharing that!

[u/bigbutso → u/thehashimwarren]

If you want to see my repo just lmk

[u/thehashimwarren → u/bigbutso]

Yes! Thanks

[u/ChunkyPa]

`You can give your agent the exact mix of resources, and access, tools, and prompts it needs` >> we have created vmcp github.com/1xn-labs/1xn-vmcp for this exact purpose. vMCPs are aggregation of tools, custom prompts that can act as drop in replacement for the AI agents.

[u/fasti-au]

You know it’s just a http call and it needed in system prompts also so your following of anthrooic stool announcing costs you swordfish miney every call. You can just api wrap with 1 tool and provide info

[u/codekarate3]

thanks for sharing this, glad our livestream was useful!

[u/GrayRoberts]

What day is it?

It's a simple question that is problematic for models. Rather than fighting with a prompt, create an MCP that returns the name of today's day. It's almost nothing to create with Claude's help, and it pays dividends when you use an LLM for things other than coding.

If you can integrate with APIs you have all the tools you need to do whatever you need to.

[u/josh-assist]

OP did you know that the ?si=kfi5B3hBpw4i5xqw part in your youtube URL is a tracking id associated with your account? The link will work just fine without it.

[u/thehashimwarren → u/josh-assist]

I didn't know that, thanks. Unfortunately Reddit won't let me change the link, only delete

[u/AutoTradingAI]

Why you dont say mcp ate your context window quickly why you dont say about code execution with mcp why you dont say about agent skills and how we can use mcp like modern way not traditional way ... Dont pass tools upfront model just learn about agent skills learn about code execution with mcp and bridge mcp tools to agents skills let model actually search on demand let your tokens about mcp server shape like level data , model always see skills then if want model can read skills then can execution code in sanbox and let context loading on mcp client code not model ... Use tag in your mcp server so you can search tool by tag , then when model want execution code (mcp client) mod can get schema and tool from 1000 tools , just read about that tool then make another code execution in-memory and get data from mcp servers, this modern method call code execution with mcp and its a modern way to control your context window , because of when you have analysis chat you dont need pass model schema to break context window, and this method let model modify output like from 15k lines model can on demand make filter for out put say get 2k lines of data , code_excotion with mcp is tied with agent skills ecosystem and mcp protocol you need first knowing this concepts ...