Agent Skills is now an open standard
83 comments
·December 18, 2025an0malous
lxgr
This isn’t just a standard—this is a templating system that could offer us a straight shot to AGI!
allisdust
Please consider donating this to the Linux Foundation so they can drive this inspiring innovation forward.
acedTrex
Have you considered publishing this with a few charts about vague levels of "correctness"?
rvz
What is "correctness?"... wait hang on let me think...
"you're absolutely right!"
InitialLastName
Luckily you get the "extremely confident, even when wrong" attribute for free.
brap
Give this man a Turing Award
null
weitendorf
announcing md2ai spec
oblio
> logical
Please tell us how REALLY feel about JavaScript.
apf6
It was just a few months ago that the MCP spec added a concept called "prompts" which are really similar to skills.
And of course Claude Code has custom slash commands which are also very similar.
Getting a lot of whiplash from all these specifications that are hastily put together and then quickly forgotten.
mrbonner
The agentic development scene has slowly turned into a full-blown JavaScript circus—bright lights, loud chatter, and endless acts that all look suspiciously familiar. We keep wrapping the same old problems in shiny new packages, parading them around as if they’re groundbreaking innovations. How long before the crowd grows tired of yet another round of “RFC” performances?
isoprophlex
MCP: we're uber, but for stdout
toomuchtodo
When the AI investment dollars run out. "As long as the music is playing, you've got to get up and dance." (Chuck Prince, Citigroup)
hugs
the tech industry is forever in denial that it is also actually a fashion industry.
recursive
That's only true for companies that make most of their money from investment instead of customers. Those exist too.
pixl97
Beyond assembly everything is window dressing.
rvz
Well, these agentic / AI companies don't even know what an RFC is, let alone how to write one. The last time they attempted to create a standard (MCP) it was not only premature, but it was a complete security mess.
Apart from Google Inc., I have not seen a single "AI company" propose an RFC that was reviewed by the IETF and became a proper internet standard. [0]
"MCP" was one of the worst so-called "standards" ever built since the JWT was proposed. So I do not take Anthropic seriously when they create so-called "open standards" especially when the reference implementation is in Javascript or TypeScript.
lxgr
To be fair, security wasn’t even a consideration until RFCs were well into triple digits. We’re still very early, as they say.
> I have not seen a single "AI company" propose an RFC that was reviewed by the IETF and became a proper internet standard.
Why would the IETF have anything to do with LLM/agent standards? This seems like a category error. They also don’t ratify web standards, for example.
null
good-idea
I have been switching between OpenCode and Claude - one thing I like about OpenCode is the ability to define custom agents. These can be ones tailored to specific workflows like PR reviews or writing change logs. I haven't yet attempted the equivalent of this with skills in Claude.
These two solutions look feel and smell like the same thing. Are they the same thing?
Any OpenCode users out there have any hot or nuanced takes?
reedf1
How likely are we to look back on Agent/MCP/Skills as some early Netscape peculiarity? I would dive into adoption if I didn't think some new thing would beat the paradigm in a fortnight.
xnx
Don't forget A2A: https://developers.googleblog.com/en/a2a-a-new-era-of-agent-...
We'll see how many of these are around in a few years.
isodev
How likely is it to even remember “the AI stuff” 2-3 years from now? What we’re trying to do with LLMs today is extremely unsustainable. NVidia/openai will run out of silly investors eventually…
wuliwong
So like any early phase, there's risk in picking a technology to use.
DenisM
Why do you think they will fade out?
observationist
Frontier models will eventually eat all the tedious tailored add-ons as just part of something they can do.
Right now models have roughly all of the written knowledge available to mankind, minus some obscure held out private archives and so on. They have excellent skills and general abilities to construct plausible sequences of actions to accomplish work, but we need to hold their hands to really get decent performance across a wide range of activities. Skills and agent frameworks and MCP carve out different domains of that problem, with successful solutions providing training data for future models that might be able to be either generalized, or they'll be able to create a vast mountain of synthetic data following successful patterns, and make the next generation of models incredibly useful for a huge number of tasks, by default.
It might also be possible that by studying the problem, identifying where mode collapses and issues with training prevent the right sort of generalization, they might tweak the architecture and be able to solve the deficiency through normal training runs, and thereby discard the need for all the bespoke artisanal agent specifications.
jonahbenton
To my eyes skills disappear, MCP and agent definitions do not.
You can have the most capable human available to you, a supreme executive assistant. You still have to convey your intent and needs to them, your preferences, etc, with as high a degree of specificity as necessary.
And you need to provide them with access and mechanisms to do things on your behalf.
Agentic definitions are the former, and they will evolve and grow. I like the metaphor of deal terms in financial contracts- benchmarkers document billions of these now. The "deal terms" governing the work any given entity does for you will be rich and bespoke and specific, like any valuable relationship. Even if the agent is learning about you, your governance is still needed.
MCP is the latter. It is the protocol by which a thing does things for you. It will get extensions. Skill-like directives and instructions will get delivered over it.
Skills themselves are near term scaffold that will soon disappear.
DenisM
I hear you - model development might overcome the shortcomings one day.
However the "waiting out" strategy needs a timeout. It might happen that agentic crutches around LLMs will bear fruit much sooner than high-quality LLMs arrive. If you don't have a timeout or a decent exit criteria you may end up waiting indefinitely, or at least until reality of things becomes too painful to ignore.
The "ski rental problem" comes to mind here, but maybe there is another "wait it out" exit strategy?
mbesto
> Right now models have roughly all of the written knowledge available to mankind, minus some obscure held out private archives and so on.
Sorry for the nit, but this is a gross oversimplification. Most private archives are not obscure but obfuscated and largely are way more valuable training data then the publicly available ones.
Want to know how the DOD may technically tracks your phone? Private.
Want to know how to make Coca Cola at scale? Private.
Want to know what the schematic is for a Google TPU? Private.
etc etc.
amitport
His point, I believe, was that it is early in the innovation cycle and they very well be replaced quickely with different solutions/paradigms.
DenisM
Well, some things fade out and some do not. How do we decide which one it is?
The reason I ask is that the pace of new things arriving is overwhelming, hence I was tempted to just ignore it. Not because things had signs of transience, but because I was drowning and didn't know where to start. That is not the same thing as actually observing signs of things being too foamy.
wuliwong
Agreed. I think if this is overly concerning, developing early in the innovation cycle just might not be the ideal place to be. :)
orliesaurus
Adoption on most of these has been weak, except MCP (and whatever flavor of markdown file you like to add to your agent context)
zingababba
Microsoft seems to be pushing MCP pretty hard in the Azure ecosystem. My cynical take is they are very aware of the context bloat so see it as extra inference $$.
smrtinsert
Extremely likely but that doesn't mean it lacks value today
unbelievably
Why does this need to be a standard in the first place. This isn't DDR5 lol, it's literally just politely asking the model to remember some short descriptions and read a corresponding file when it thinks appropriate. I feel like these abstractions are supposed to make Claude sound more sophisticated because WOW now we can give the guy new skills! But really they're just obfuscating the "data as code" aspect of LLMs which is their true power (and vulnerability ofc).
makestuff
Is a skill essentially a reusable prompt that is inserted at the start of any query? The marketing of Agents/MCP/skills/etc is very confusing to me.
cshimmin
It's basically just a way for the LLM to lazy-load curated information, tools, and scripts into context. The benefit of making it a "standard" is that future generations of LLMs will be trained on this pattern specifically, and will get quite good at it.
prodigycorp
Does it persist the loaded information for the remainder of the conversation or does it intelligently cull the context when it's not needed?
brabel
Each agent will do that differently, but Gemini CLI, for example, lets you save any session with a name so you can continue it later.
stavros
It's the description that gets inserted into the context, and then if that sounds useful, the agent can opt to use the skill. I believe (but I'm not sure) that the agent chooses what context to pass into the subagent, which gets that context along with the skill's context (the stuff in the Markdown file and the rest of the files in the FS).
This may all be very wrong, though, as it's mostly conjecture from the little I've worked with skills.
danielbln
Its part of managing the context. It's a bit of prepared context that can be lazy-loaded in as the need arises.
Inversely, you can persist/summarize a larger bit of context into a skill, so a new agent session can easily pull it in.
So yes, it's just turtles, sorry, prompts all the way down.
theshrike79
Skills can be just instructions how to do things.
BUT what makes them powerful is that you can include code with the skill package.
Like I have a skill that uses a Go program to traverse the AST of a Go project to find different issues in it.
You COULD just prompt it but then the LLM would have to dig around using find and grep. Now it runs a single executable which outputs an LLM optimised clump of text for processing.
langitbiru
It also has (Python/Ruby/bash) scripts which Claude Code can execute.
quacky_batak
i like how Anthropic has positioned themselves as the true AI research company and donating “standards” like that.
Although Skills are just md files but it’s good to see them “donate” it.
There goal seems to be simple: Focus on coding and improving it. They’ve found a great niche and hopefully revenue generating business there.
OpenAI on the other hand doesn’t give me same vibes, they don’t seem very oriented. They’re playing catchup with both Google models and Anthropic
plufz
I have no idea why I’m about to defend OpenAI here. BUT OpenAI have released some open weight models like gpt-oss and whisper. But sure open weight not open source. And yeah I really don’t like OpenAI as a company to be clear.
dismantlethesun
They have but it does feel like they are developing a closed platform aka Apple.
Apple has shortcuts, but they haven’t propped it up like a standard that other people can use.
To contrast this is something you can use even if you have nothing to do with Claude, and your tools created will be compatible with the wider ecosystem.
theshrike79
A skill can also contain runnable code.
Many many MCPs could and should just be a skill instead.
layer8
They published a specification, that doesn’t yet make it a standard.
runtimepanic
Interesting move. One thing I’m curious about is how opinionated the standard is supposed to be. In practice, agent “skills” tend to blur the line between capabilities, tools, and workflows, especially once statefulness and retries enter the picture. Is the goal here mostly interoperability between agent frameworks, or do you see this evolving into something closer to a contract for agent behavior over time? I can imagine standardization helping a lot, but only if it stays flexible enough to avoid freezing today’s agent design assumptions.
robertheadley
I had developed a tool for Roo Code, and have moved over to anti-gravity with no problem, that basically gives playwright the ability to develop and test user scripts in an automated fashion.
It is functionally a skill. I suppose once anti-gravity supports skills, I will make it one officially.
vladsh
Skills are a pretty awkward abstraction. They emerged to patch a real problem, generic models require fine-tuning via context, which quickly leads to bloated context files and context dilution (ie more hallucinations)
But skills dont really solve the problem. Turning that workaround into a standard feels strange. Standardizing a patch isn’t something I’d expect from Anthropic, it’s unclear what is their endgame here
ako
Skill don’t solve the problem if you think an llm should know everything. But if you see LLMs mostly as a text plan-do-check-act machine that can process input text, generate output text, and can create plans how to validate the output, without knowing everything upfront, skills are perfectly fine solution.
You need a practical and efficient way to give the llm your context. Just like every organization has its own standards, best practices, architectures that should be documented, as new developers do not know this upfront, LLMs also need your context.
An llm is not an all knowing brain, but it’s a plan-do-check-act text processing machine.
brabel
How would you solve the same problem? Skills seem to be just a pattern (before this spec) that lets the LLMs choose what information they need to "load". It's not that different from a person looking up the literature before they do a certain job, rather than just reading every book every time in case it comes in handy one day. Whatever you do you will end up with the same kind of solution, there's no way to just add all useful context to the LLM beforehand.
root_axis
> it’s unclear what is their endgame here
Marketing. That defines pretty much everything Anthropic does beyond frontier model training. They're the same people producing sensationalized research headlines about LLMs trying to blackmail folks in order to prevent being deleted.
wuliwong
>But skills dont really solve the problem.
I think that they often do solve the problem, just maybe they have some other side effects/trade offs.
theshrike79
They’re not a perfect solution, but they are a good one.
The best one we have thought of so far.
I feel inspired and would like to donate my standard for Agent Personas to the community. A persona can be defined by a markdown file with the following frontmatter: