Agents increasingly work with large files, large tool catalogs, and large context. Loading everything upfront wastes tokens, degrades performance, and overwhelms both model and user. Progressive disclosure - revealing detail only when needed - is a design principle that applies to more than traditional UI. It applies to how agents encounter and use information.
AI agents can pursue wrong directions for a long time before producing output. By the time you see the result, significant time and tokens are wasted. The alternative - exposing the agent's reasoning in real time - adds cognitive load and can feel noisy. The design question: when should users see the agent's thinking, and when should they be able to interrupt?
A background agent completes 90% of a task. The remaining 10% needs human judgment - a nuance the agent missed, a decision that requires context the agent doesn't have. If the handoff from "agent working" to "human editing" is clunky, you've just negated the benefit of automation. The transition is a design problem.