I used Claude to author a process document for my team. After a lot of back and forth, it produced a thorough 4,000-word doc. And then I spent the next 30 minutes reading it, line by line, making sure every recommendation matched my intention.
The AI produced the document in minutes. I evaluated it at human reading and review speed.
Jakob Nielsen has a name for this bottleneck: evaluability. He argues it should replace execution efficiency as the central UX metric:
In command-based UIs, the user’s primary cognitive load was executing the task step-by-step. In intent-based systems, execution is cheap, but evaluation becomes the bottleneck. The usability metric shifts to how rapidly and accurately a user can verify that the AI’s output matches their actual goal. Interfaces must be optimized for “evaluability,” allowing users to judge quality and appropriateness without painstakingly combing through every detail of the result.
“Without painstakingly combing through every detail” is exactly what I was doing with my 4,000-word document. We don’t have the interfaces for this yet. We’re still reading AI output the way we’d read something a colleague wrote, except a colleague wouldn’t hand me 4,000 words and say “check this.” (Unless of course, they wrote it with AI and then, of course they would.)
In agentic engineering, you often hear that code review is the bottleneck.
Nielsen again:
Our designs must not act as cognitive wheelchairs that replace human agency; they must act as cognitive exoskeletons that support and enhance human flourishing, even as traditional work vanishes. Good AI UX will teach just enough, reveal plan structures, and leave a comprehensible trail of action so users can maintain digital judgment.
Most AI interfaces are optimized for generation speed. The harder problem is on the other end: helping humans evaluate what got generated. Until we solve that, productivity gains from AI come with an evaluation tax paid at human speed.

Intent by Discovery: Designing the AI User Experience
AI is not just a better chat box. It changes the user’s role from operator to supervisor, which forces UX to move from command-based interaction toward intent-based delegation, new usability metrics, orchestration layers, calibrated friction, and ultimately exploration-based interaction to clarify the user’s needs.





















