When does a repeated element deserve its own component? Anton Sten is using an AI agent to build his design system. He measures its value by the decisions it saves people. Here’s his filter for what belongs:
Lately I’ve been using a simple filter before adding anything to a system. Does it show up often enough to deserve a shared solution? Does it have behavior or states that need to stay consistent? Is there an actual rule here that we want to encode rather than leave to individual judgment? And, just as importantly, is this something someone is willing to own over time?
The third question is the one I keep coming back to. Repetition alone isn’t enough. Something becomes valuable as part of a system when it captures a decision we don’t want humans or agents to keep making independently.
I’d treat the owner question as part of that decision, too. Someone has to remain responsible for the rule as the product changes. Otherwise, the team has standardized something without deciding who can resolve the next exception.
Once a rule is shared, people and agents still need to recognize when it applies. Sten uses token names to show how:
Take naming.
green-600tells you what something looks like.text/successtells you what it’s for. A designer with years of context may know which green is appropriate, and an engineer may remember which one the team normally uses, but an agent only has the system in front of it.The more intent the system contains, the less any of its users have to infer. Semantic naming is not just a preference in that context; it carries the decision across design, code and the agents working between them. That clarity helps people too, but agents expose just how much ambiguity we’ve historically allowed humans to compensate for.

The point of a system is fewer decisions
A good design system captures decisions so people and agents do not have to keep making them independently.


















