A product streams a model's answer token by token, shows which tools it is calling, and lets the user stop it. Design that UI, including what happens when the user hits Stop or navigates away.
Answer it out loud before you open anything. The value of the flags below is in comparing them to what you actually said.
The situation behind the question
An assistant panel inside a larger application. Answers can take a while, cite documents, call tools that modify data, and users frequently switch tabs or navigate mid-answer.
What it is really testing
Whether the candidate treats a stream as long-lived, cancellable, partially-correct state rather than as a fancy loading spinner. The tool calls that modify data are the discriminator: stopping the render is not stopping the work.