AI Research & Frontier Labs · August 2026
Ben Lorica had asked the definitional question the field keeps stepping around: what actually makes a system an agent? Grootendorst answers by deflating it, noting first that the thing changes every two months. Lorica's immediate reply is that he has just described what people now call the harness.
So
in your mind, what makes a system agent?
Yeah, that's actually been one of the more complex topics for us to actually describe because the field has been changing so quickly. And what is fundamentally an agent when it changes every two months? It's a little bit of a hot take, but I really do think that an agent is an LLM in a for loop with some tools, some memory, and perhaps some guardrails. And that really is essentially it. It all boils down to its base.
So you just described the harness, basically. So now people are also the hot term right now is harness engineering.
Yeah. Yeah.
So where are teams do you think what is the real progress and what is just marketing when it comes to agents?