MCP Doesn't Need 30 Tools: It Needs Code

https://lucumr.pocoo.org/2025/8/18/code-mcps/

33•the_mitsuhiko•1h ago

Comments

yxhuvud•51m ago

First rule of writing about something that can be abbreviated: First have some explanation so people have an idea of what you are talking about. Either type out what the abbreviation stands for, have an explanation or at least a link to some other page that explain what is going on.

diggan•47m ago

> or at least a link to some other page that explain what is going on

There is a link to a previous post by the same author (within the first ten words even!), which contains the context you're looking for.

yxhuvud•43m ago

A link to a previous post is not enough, though of course appreciated. But it would be something I click on after I decide if I should spend time on the article or not. I'm not going on goose chases to figure out what the topic is.

dkdcio•19m ago

this is a wild position. it would have taken you the same amount of time to type your question(s) into your favorite search engine or LLM to learn what the terms mean as you now have spent on this comment thread. the idea that every article should contain all prerequisite knowledge for anybody at any given level of context about any topic is absurd

reactordev•47m ago

MCP is Model Context Protocol, welcome to the land of the living. Make sure you turn the lights off to the cave. :)

It’s pretty well known by now what MCP stands for, unless you were referring to something else…

klez•43m ago

I, for one, still need to look it up every time I see it mentioned. Not everyone is talking or thinking about LLMs every waking minute.

reactordev•40m ago

I figured with all the AI posts and models, tools, apps, featured on here in the last year or two that it was a given. I guess not.

grim_io•4m ago

Are you looking up what the abbreviation stands for, or what an MCP is?

The first case doesn't matter at all if you already know what an MCP actually is.

At least for the task of understanding the article.

koakuma-chan•18m ago

> It’s pretty well known by now what MCP

Minecraft Coder Pack

tronreference•9m ago

Master Control Program:

https://www.youtube.com/watch?v=atmQjQjoZCQ

jeroenhd•33m ago

If you don't know the abbreviation, that can also mean you're not the target audience. This is a blog post written for an audience that uses multiple MCP servers, arguing for a different way to use LLMs. If you need the term explained and don't care enough to throw the abbreviation into Google, you're not going to care much about what's being said anyway.

I have no idea what any of the abbreviations in stock market news mean and those stock market people won't know their CLIs from their APIs and LLMs, but that doesn't mean the articles are bad.

jahsome•22m ago

Are you referring to MCP? If so, it's fully spelled out in the first sentence of the first paragraph, and links to a more thorough post on the subject. That meets 2 of the 3 criteria you've dictated.

xavierx•40m ago

Is this just code injection?

It’s talking about passing Python code in that would have a Python interpreter tool.

Even if you had guardrails setup that seems a little chancery, but hey this is the time of development evolution where we’re letting AI write code anyway, so why not give other people remote code execution access, because fuck it all.

preek•24m ago

Re Security: I put my AI assistant in a sandbox. There, it can do whatever it wants, including deleting or mutating anything that would otherwise be harmful.

I wrote about how to do it with Guix: https://200ok.ch/posts/2025-05-23_sandboxing_ai_tools:_how_g...

Since then, I have switched to using Bubblewrap: https://github.com/munen/dotfiles/blob/master/bin/bin/bubble...

philipp-gayret•23m ago

Agree on that it should be composable. Even better if MCP tooling wouldn't yield huge amounts of output that pollutes the context and the output of one can be input to the next, so indeed that may as well be code.

Would be nice if there was a way for agents to work with MCPs as code, preview or debug the data flowing through them. At the moment it all seems not a mature enough solution and Id rather mount a Python sandbox with API keys to what it needs than connect an MCP tool on my own machine.

juanviera23•18m ago

I agree MCP has these flaws, idk why we need MCP servers when LLMs can just connect to the existing API endpoint

Started on working on an alternative protocol, which lets agents call native endpoints directly (HTTP/CLI/WebSocket) via “manuals” and “providers,” instead of spinning up a bespoke wrapper server: https://github.com/universal-tool-calling-protocol/python-ut...

even connects to MCP servers

if you take a look, would love your thoughts

faangguyindia•11m ago

Here is why MCP is bad, here i am trying to use MCP to build a simple node cli tool to fetch documentation from Context7: https://pastebin.com/raw/b4itvBu4 And it doesn't work even after 10 attemps.

Fails and i've no idea why, meanwhile python code works without issues but i can't use that one as it conflicts with existing dependencies in aider, see: https://pastebin.com/TNpMRsb9 (working code after 5 failed attempts)

I am never gonna bother with this again, it can be built as a simple rest API, why we even need this ugly protocol?

CharlieDigital•3m ago

A few weeks back, I actually started working on an MCP server that is designed to let the LLM generate and execute JavaScript in a sandboxed C# runtime with Jint.

https://github.com/CharlieDigital/runjs

Let's the LLM safely generate and execute whatever code it needs.

It has a built in secrets manager API, HTTP fetch analogue, JSONPath for JSON handling, and Polly for HTTP request resiliency.

jumploops•2m ago

The promise of MCP is that it “connects your models with the world”[0].

In my experience, it’s actually quite the opposite.

By giving an LLM a set of tools, 30 in the Playwright case from the article, you’re essentially restricting what it can do.

In this sense, MCP is more of a guardrail/sandbox for an LLM, rather than a superpower (you must choose one of these Stripe commands!).

This is good for some cases, where you want your “agent”[1] to have exactly some subset of tools, similar to a line worker or specialist.

However it’s not so great when you’re using the LLM as a companion/pair programmer for some task, where you want its output to be truly unbounded.

[0]https://modelcontextprotocol.io/docs/getting-started/intro

[1]For these cases you probably shouldn’t use MCP, but instead define tools explicitly within one context.

GitHub Copilot for Xcode – The Heist of the Century?

Physically Based Rendering in Filament

Eavesdropping on Phone Conversations Through Vibrations

Always Inadequate

The new geography of stolen goods

MapLibre Tile: A next generation geospatial format optimized for rendering

How I Made Ruby Faster Than Ruby

Show HN: Edit videos in browser without uploads, signups, or complex software

What My Daughter Told ChatGPT Before She Took Her Life

Meta Hypernova: The first real contender for the post-Smartphone era

Show HN: A map of your favorite artists' upcoming concerts

6 Reasons You Don't Need an SRE Team

Everyone should own a 3D printer in 2025

Ronnie Rondell Jr: Veteran stuntman set on fire for Pink Floyd album cover dies

LLMs and Coding Agents = Security Nightmare

Website Is Served from Nine Neovim Buffers on My Old ThinkPad

NMS Ceefax

TimeTracker – A self-hosted, team time tracker with timers, and reporting

The Network Times: AI Cluster Networking

Buypass Terminates Issuance of GoSSL Certificates

Forums for devs interested in systems, like kernel dev/ networks etc.?

Show HN: Instant visa-compliant insurance certificates for Moroccan travelers

Mozilla Firefox Is Dying

AI coding is plateauing but also accelerating

Chili's was a 90s relic, now it's America's hottest restaurant

The Plan to Turn the Caribbean's Glut of Sargassum into Biofuel

Data Centers Need to Bring Own Power Supply, Grid Watchdog Says

Show HN: Engagerly – Turn Discord Members Active with Gamified Rewards

Ask HN: What's the best way to extract text from information dense pdfs?

Why we dont like TDD