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I'm ready to accept a definition of "agent" that I think is widely-enough agreed upon to be useful, at least in the AI engineering space: An LLM agent runs tools in a loop to achieve a goal (I've been dismissing the term as hopelessly ambiguous for years) simonwillison.net/2025/Sep/18/...

simonwillison.netI think “agent” may finally have a widely enough agreed upon definition to be useful jargon nowI’ve noticed something interesting over the past few weeks: I’ve started using the term “agent” in conversations where I don’t feel the need to then define it, roll my eyes …

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Why a loop? An “agentic flow” can be trigger -> action ? I ask because I’ve seen previous descriptions using loop but I’m not sure why the idea of continuous execution makes it more “agentic”

That to me sounds like just bad computer science. In what other context would you say "this algorithm can take indefinite time and resources for a given task" and someone would be ok with it? Tasks have values, they need to take bounded time and cost.

I agree it's part of what agents are doing but I can't see how it's a good idea. Good algorithms are predictable. Like at minimum I'd want to bound the number of steps taken. These things cost money, and tasks they might do are often not worth that much.

Hmm. The industry’s been using “user agent” to describe software agents responsible for retrieving and facilitating user interaction with web content for a very long time. Web browsers, download managers, feed readers, email clients, etc.

Agreeing with the general premise of your post, I’d venture that “user agent”, “software program”, “software system”, or even “software agent” are more apt phrases than “LLM agent” in most (perhaps all?) scenarios.

Amusingly, Wikipedia only lists “Web browsing” under “Agentic AI” applications, other than linking to the MIT study spotlighting “95% of enterprise generative-AI pilots fail to deliver measurable P&L impact”. User agent and software agent wiki pages have myriad real world examples listed.

Strictly speaking, LLM agents on their own don’t run tools in a loop to achieve a goal. LLMs generate text. Some software systems, augmented by subsystems and integrations, run tools in a loop based on rules & logic, sometimes incorporating outputs from generative pre-trained transformers as inputs.

i hate the term agent because it’s paired with the term autonomous which is just so completely unreliable and discongruent with just about every experience in technology today. what we have now is a probabilistic rules engine at best.

Yeah I avoid the word "autonomous" as much as I can, I think it makes these systems sound far more capable than they actually are If you didn't give the system a specific goal to achieve what are you even doing? Sounds like science fiction to me at that point

Well, if you want vague and inconsistent, there is the glaring I in the AI bit. What is intelligence with respect to AI...? (rhetorical question). Tech loves to fuck with language.

Like your definition, however, be better not to call them agents at all. Another case of anthropomorphism with AI (implying human characteristics they don't have) If something is called an agent, it must, in some sense, have agency, which, as you say, they don't.

I tried the "don't call anything agents" thing for a couple of years, but it feels counter-productive at this point - plenty of people are "building agents" now where what they mean is "LLMs achieving goals by running tools in a loop" and I want to be able to have conversations with them about it

I’m curious how you define agency in such a way to exclude these things. Lacking “the capacity, condition, or state of acting or of exerting power” or not being a “thing through which power is exerted or an end is achieved?”

merriam-webster.comDefinition of AGENCYthe office or function of an agent; the relationship between a principal and that person's agent; the capacity, condition, or state of acting or of exerting power : operation… See the full definition

I think this is a standard weak/strong double use thing. the agency agents are supposed to have is in deciding what to do each loop call in service of the goal they're given. that's a very limited and derivative form of agency but it's too strong to say there's nothing resembling agency in the mix

Aren't you (the Steve who acts in the world) to some extent "a thing you (the Steve of desires and hopes) have delegated agency to"? Where sits the smallest homunculus? Does it exist? Or is agency just a post hoc rationalization for irrational urges? Is my hand an agent of my mind, or vice versa?