The Bitter Lesson of LLM Extensions

> Skills are the actualization of the dream that was set out by ChatGPT Plugins .. But I have a hypothesis that it might actually work now because the models are actually smart enough for it to work.

and earlier Simon Willison argued[1] that Skills are even bigger deal than MCP.

But I do not see as much hype for Skills as it was for MCP - it seems people are in the MCP "inertia" and having no time to shift to Skills.

1. https://simonwillison.net/2025/Oct/16/claude-skills/

I don't see how "they improved the models" is related to the bitter lesson. You are still injecting human-level expertise (whether it is by prompts or a structured API) to compensate for the model's failures. A "bitter lesson" would be that the model can do better without any injection, but more compute power, than it could with human interference.

I believe that what we need is treating prompts as stochastic programs and using a special shell for calling them. Claude Code and Codex and other coding agents are like that - now everybody understands that they are not just coding assistants they are a general shell that can use LLM for executing specs. I would like to have this extracted from IDE tools - this is what I am working on in llm-do.

I don't know, even ChatGPT 5.1 hallucinates API's that don't exist, though it's a step forward in that it also hallucinates the non existence of APIs that exist.

But I reckon that every time that humans have been able to improve their information processing in any way, the world has changed. Even if all we get is to have an LLM be right more times than it is wrong, the world will change again.

  > "If I could short MCP, I would"

To quote the Systems Bible, any working complex system is only the result of the growth of a working simple system -- MCP seems to me to be right on the edge of what you'd define as a "working simple system" -- but to the extent it's all torn down for something simpler, that thing will inevitably evolve to allow API specifications, API calls, and streaming interaction modes.

Anyway, I'm "neutral" on MCP, which is to say I don't love it. But I don't have a better system in mind, and crucially, because these models still need fine-tuning to deal properly with agent setups, I think it's likely here to stay.