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What if you don't need MCP at all?

mariozechner.at

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Re: What if you don't need MCP at all?

#91

Post by rsanheim »

nestorD wrote: post #39

So far I have seen two genuinely good arguments for the use of MCPs: * They can encapsulate (API) credentials, keeping those out of reach of the model, * Contrary to APIs, they can change their interface whenever they want and with little consequences.

But …you have to give the MCP the creds somehow. Maybe it’s via a file on disk (bad), maybe via an env var (less bad). Maybe you do it via your password CLI that you biometricly auth to, which involves a timeout of some sort for security, but that often means you can’t leave an agent unattended.

In any case, how is any of this better than a CLI? CLIs have the same access models and tradeoffs, and a persistent agent will plumb the depths of your file system and environment to find a token to do a thing if your prompt was “do a thing, use tool/mcp/cli”.

So where is this encapsulation benefit?

Re: What if you don't need MCP at all?

#92

Post by whoknowsidont »

paulddraper wrote: post #87
whoknowsidont wrote: post #15

MCP was a really shitty attempt at building a plugin framework that was vague enough to lure people into and then allow other companies to build plugin platforms to take care of the MCP non-sense. "What is MCP, what does it bring to the table? Who knows. What does it do? The LLM stuff! Pay us $10 a month thanks!" LLM's have function / tool calling built into them. No major models have any direct knowledge of MCP. Not…

> No major models have any direct knowledge of MCP. Claude and ChatGPT both support MCP, as does the OpenAI Agents SDK. (If you mean the LLM itself, it is "known" at least as much as any other protocol. For whatever that means.)

>it is "known" at least as much as any other protocol.

No. It is not. Please understand what the LLM's are doing. Claude nor ChatGPT nor any major model knows what MCP is.

They know how to function & tool call. They have zero trained data on MCP.

That is a factual statement, not an opinion.

Re: What if you don't need MCP at all?

#93

Post by cjonas »

whoknowsidont wrote: post #85
upghost wrote: post #43

So I don't disagree with any of the criticisms of MCPs but no one here has mentioned why they are useful, and I'm not sure that everyone is aware that MCP is actually just a wrapper over existing cli/API: 1. Claude Code is aware of what MCPs it has access to at all times. 2. Adding an MCP is like adding to the agent's actuators/vocabulary/tools because unlike cli tools or APIs you don't have to constantly remind it w…

>This effect is _significantly_ stronger than putting info about available API/cli into CLAUDE.md. No it's not. Honestly this conversation is extremely weird to me because somehow people are gravely misunderstanding what MCP even purports to do, let alone what it actually CAN do in the most ideal situation. It is a protocol and while the merits of that protocol is certainly under active discussion it's irrelevant bec…

This response is spot on. People seem very confused about what MCP actually is. It's just a standard way to provide an LLM with tools. And even how that happens is up to the agent implementation. There are some other less common features, but the core is just about providing tool definitions and handling the tool_call. Useful but basically just OpenAPI for LLM

Re: What if you don't need MCP at all?

#94

Post by smallnamespace »

whoknowsidont wrote: post #85
upghost wrote: post #43

So I don't disagree with any of the criticisms of MCPs but no one here has mentioned why they are useful, and I'm not sure that everyone is aware that MCP is actually just a wrapper over existing cli/API: 1. Claude Code is aware of what MCPs it has access to at all times. 2. Adding an MCP is like adding to the agent's actuators/vocabulary/tools because unlike cli tools or APIs you don't have to constantly remind it w…

>This effect is _significantly_ stronger than putting info about available API/cli into CLAUDE.md. No it's not. Honestly this conversation is extremely weird to me because somehow people are gravely misunderstanding what MCP even purports to do, let alone what it actually CAN do in the most ideal situation. It is a protocol and while the merits of that protocol is certainly under active discussion it's irrelevant bec…

Three facts to consider:

1. CLAUDE.md is not part of the system prompt

2. The Claude Code system prompt almost certainly gives directions about how to deal with MCP tools, and may also include the list of tools

3. Instruction adherence is higher when the instructions are placed in the system prompt

If you put these three facts together then it’s quite likely that Claude Code usage of a particular tool (in the generic sense) is higher as an MCP server than as a CLI command.

But why let this be a limitation? Make an MCP server that calls your bash commands. Claude Code will happily vibe code this for you, if you don’t switch to a coding tool that gives better direct control of your system prompt.

Re: What if you don't need MCP at all?

#95

Post by choilive »

whoknowsidont wrote: post #92
paulddraper wrote: post #87

Earlier quoted context omitted.

> No major models have any direct knowledge of MCP. Claude and ChatGPT both support MCP, as does the OpenAI Agents SDK. (If you mean the LLM itself, it is "known" at least as much as any other protocol. For whatever that means.)

>it is "known" at least as much as any other protocol. No. It is not. Please understand what the LLM's are doing. Claude nor ChatGPT nor any major model knows what MCP is. They know how to function & tool call. They have zero trained data on MCP. That is a factual statement, not an opinion.

That is an easily falsifiable statement. If I ask ChatGPT or Claude what MCP is Model Context Protocol comes up, and furthermore it can clearly explain what MCP does. That seems unlikely to be a coincidental hallucination.

Re: What if you don't need MCP at all?

#96

Post by Bockit »

whoknowsidont wrote: post #92
paulddraper wrote: post #87

Earlier quoted context omitted.

> No major models have any direct knowledge of MCP. Claude and ChatGPT both support MCP, as does the OpenAI Agents SDK. (If you mean the LLM itself, it is "known" at least as much as any other protocol. For whatever that means.)

>it is "known" at least as much as any other protocol. No. It is not. Please understand what the LLM's are doing. Claude nor ChatGPT nor any major model knows what MCP is. They know how to function & tool call. They have zero trained data on MCP. That is a factual statement, not an opinion.

This is probably a semantics problem. You’re right. The models don’t know how to mcp. The harness they run in does though (Claude code, Claude desktop, etc), and dynamically exposes mcp tools as tool calls.

Re: What if you don't need MCP at all?

#97

Post by llbbdd »

Bockit wrote: post #96
whoknowsidont wrote: post #92

Earlier quoted context omitted.

>it is "known" at least as much as any other protocol. No. It is not. Please understand what the LLM's are doing. Claude nor ChatGPT nor any major model knows what MCP is. They know how to function & tool call. They have zero trained data on MCP. That is a factual statement, not an opinion.

This is probably a semantics problem. You’re right. The models don’t know how to mcp. The harness they run in does though (Claude code, Claude desktop, etc), and dynamically exposes mcp tools as tool calls.

HN loves inventing semantics problems around AI. It's gotten really, really annoying and I'm not sure the people doing it are even close to understanding it.

Re: What if you don't need MCP at all?

#98

Post by numpad0 »

whoknowsidont wrote: post #92
paulddraper wrote: post #87

Earlier quoted context omitted.

> No major models have any direct knowledge of MCP. Claude and ChatGPT both support MCP, as does the OpenAI Agents SDK. (If you mean the LLM itself, it is "known" at least as much as any other protocol. For whatever that means.)

>it is "known" at least as much as any other protocol. No. It is not. Please understand what the LLM's are doing. Claude nor ChatGPT nor any major model knows what MCP is. They know how to function & tool call. They have zero trained data on MCP. That is a factual statement, not an opinion.

(pedantry)it's something humans are talking about a lot, so up-to-date models do know about it...

Re: What if you don't need MCP at all?

#99

Post by whoknowsidont »

choilive wrote: post #95
whoknowsidont wrote: post #92

Earlier quoted context omitted.

>it is "known" at least as much as any other protocol. No. It is not. Please understand what the LLM's are doing. Claude nor ChatGPT nor any major model knows what MCP is. They know how to function & tool call. They have zero trained data on MCP. That is a factual statement, not an opinion.

That is an easily falsifiable statement. If I ask ChatGPT or Claude what MCP is Model Context Protocol comes up, and furthermore it can clearly explain what MCP does. That seems unlikely to be a coincidental hallucination.

Training data =/= web search

Both ChatGPT and Claude will perform web searches when you ask them a question, which the fact that you got this confused is ironically topical.

But you're still misunderstanding the principle point because at some point these models will undoubtedly have access to that data and be trained on it.

But they didn't need to be, because LLM function & tool calling is already trained on these models and MCP does not augment this functionality in any way.

Re: What if you don't need MCP at all?

#100

Post by whoknowsidont »

Bockit wrote: post #96
whoknowsidont wrote: post #92

Earlier quoted context omitted.

>it is "known" at least as much as any other protocol. No. It is not. Please understand what the LLM's are doing. Claude nor ChatGPT nor any major model knows what MCP is. They know how to function & tool call. They have zero trained data on MCP. That is a factual statement, not an opinion.

This is probably a semantics problem. You’re right. The models don’t know how to mcp. The harness they run in does though (Claude code, Claude desktop, etc), and dynamically exposes mcp tools as tool calls.

>dynamically exposes mcp tools as tool calls.

It doesn't even do that. It's not magic.

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