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When does MCP make sense vs CLI?

ejholmes.github.io

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Re: When does MCP make sense vs CLI?

#161

Post by bonoboTP »

> When Claude does something unexpected with Jira, I can run the same jira issue view command and see exactly what it saw. Same input, same output, no mystery.

A sign of bad UX. There should be better ways to drill down into what actually happened than ctrl+o which still hides a lot and then ctrl+e is still not enough and there are some verbose flags that show absolutely everything instead of letting me check just what I want. So I'm vibe coding my own tool to do this based on the jsonl files in the Claude history directory. But this should work out of the box.

Re: When does MCP make sense vs CLI?

#163

Post by ejholmes »

fny wrote: post #143
umairnadeem123 wrote: post #83

> I tried to avoid writing this for a long time, but I'm convinced MCP provides no real-world benefit IMO this is 100% correct and I'm glad someone finally said it. I run AI agents that control my entire dev workflow through shell commands and they are shockingly good at it. the agent figures out CLI flags it has never seen before just from --help output. meanwhile every MCP server i've used has been a flaky process…

I hate MCP servers That said the core argument for MCP servers is providing an LLM a guard-railed API around some enterprise service. A gmail integration is a great example. Without MCP, you need a VM as scratch space, some way to refresh OAuth, and some way to prevent your LLM from doing insane things like deleting half of your emails. An MCP server built by trusted providers solves all of these problems. But that's…

I always get a kick out of seeing MCP wrappers around CLI’s.

Re: When does MCP make sense vs CLI?

#164

Post by nickstinemates »

AI Agent's like Claude Code are an arms race to the bottom. Just like frontier model quality, they all converge on feature sets over time (plan mode, skills, remote execution, sandboxing, etc.,) and opencode is holding its own, preferred even, in a lot of cases.

The real differentiated value comes from the environment the AI Agent operates in, the runtime.

The runtime is agent agnostic but provides a stable interface to your domain. People tried this with MCP, but MCP is a dead end. Local tool calling is so much better. Being able to extend integrations autonomously is the way, instead of being forced in to a bloated bag of tools.

This is why we built swamp - https://swamp.club. We can integrate with any technology with an API, CLI, or code base and build repeatable, typed, validated automation workflows. There are no providers to wait for. No weird tool call paths trying to get the right concoction of MCP. The agent builds the integration itself, on the spot, in minutes.

Re: When does MCP make sense vs CLI?

#165

Post by cglan »

ejholmes wrote: post #163
fny wrote: post #143

Earlier quoted context omitted.

I hate MCP servers That said the core argument for MCP servers is providing an LLM a guard-railed API around some enterprise service. A gmail integration is a great example. Without MCP, you need a VM as scratch space, some way to refresh OAuth, and some way to prevent your LLM from doing insane things like deleting half of your emails. An MCP server built by trusted providers solves all of these problems. But that's…

I always get a kick out of seeing MCP wrappers around CLI’s.

They make a big difference. For example if you use the Jira cli, most LLMs aren’t trained on it. A simple MCP wrapper makes a huge difference in usability unless you’re okay having the LLM poke and prod a bunch of different commands

Re: When does MCP make sense vs CLI?

#166

Post by fasbiner »

FINDarkside wrote: post #114
fasbiner wrote: post #100

Earlier quoted context omitted.

I would spend less time with theory and more time with practice to understand what people are getting at. MCP and CLI could, in theory, be the same. But in practice as it stands today, they are not. > MCP is just a way to write this in a structured way, Nope! You are not understanding or are actively ignoring the difference which has been explained by 20+ comments just here. It's not a controversial claim, it's a mut…

> then you should create an example repo that shows the playwright CLI and playwright MCP add the same number of tokens to context and that both are equally configurable in this respect That's just implementation detail of how your agent harness decides to use MCP. CLI and MCP are on different abstraction layers. You can have your MCP available through CLI if you wish so.

Please, please, please actually do this yourself or read any of the top comments. You are still missing the point, which you will understand if you actually do this and then look at the logs.

Re: When does MCP make sense vs CLI?

#167

Post by __MatrixMan__ »

As far as I'm aware, all of the benefits of MCP over CLI go away if you just bother to run your agents as OS users with locked down permissions such that they only have access to secrets for similarly locked down users on remote systems.

We've had decades to come up with systems for restricting what users can do, there's no reason to reinvent the wheel just because this user happens to be an AI.

Re: When does MCP make sense vs CLI?

#168

Post by notepad0x90 »

umairnadeem123 wrote: post #83

> I tried to avoid writing this for a long time, but I'm convinced MCP provides no real-world benefit IMO this is 100% correct and I'm glad someone finally said it. I run AI agents that control my entire dev workflow through shell commands and they are shockingly good at it. the agent figures out CLI flags it has never seen before just from --help output. meanwhile every MCP server i've used has been a flaky process…

Strongly disagree, despite that meaning I'm swimming upstream here.

Unlike cli flags, with MCP I can tune the comments for the tool more easily (for my own MCPs at least) than a cli flag. You can only put so much in a cli --help output. The error handling and debugability is also nicer.

Heck, I would even favor writing an MCP tool to wrap cli commands. It's easier for me to ensure dangerous flags or parameters aren't used, and to ensure concrete restrictions and checks are in place. If you control the cli tools it isn't as bad, but if you don't, and it isn't a well known cli tool, the agent might need things like vague errors explaing to it a bit.

MCP is more like "REST" or "GRPC", at the simplest level just think of it as a wrapper.

You mentioned redirecting to files, what if the output is too much that way, you'll still burn tokens. But with MCP, if the output is too much you can count the tokens and limit, or... better yet you can paginate so that it gets some results, it sees how many results there are and either decides to re-run the tool with params that will yield less results, or consume the results page-by-page.

Re: When does MCP make sense vs CLI?

#169

Post by rick1290 »

umairnadeem123 wrote: post #83

> I tried to avoid writing this for a long time, but I'm convinced MCP provides no real-world benefit IMO this is 100% correct and I'm glad someone finally said it. I run AI agents that control my entire dev workflow through shell commands and they are shockingly good at it. the agent figures out CLI flags it has never seen before just from --help output. meanwhile every MCP server i've used has been a flaky process…

When is MCP the right choice though? For example - letting internal users ask questions on top of datasets? Is it better to just offer the api openapi specs and let claude run wild? or provide an MCP with instructions?

Re: When does MCP make sense vs CLI?

#170

Post by jpbryan »

What if you want to build a third party integration to connect to Claude Chat or Cowork? Those can't run arbitrary CLIs. The only way to integrate with them is via MCP.

For good reason, IMO. Anthropic can't just allow their execution environments to run arbitrary user-generated CLI tools.

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