The command line came back.
An empty box asks you to know what's possible, what context matters, how much detail to give, and how to phrase it. We solved this once. Graphical interfaces won because picking from what you can see beats remembering what to type. Then AI shipped a text box and called it progress. I'm allowed to say that - I built one in 1993.
Context beats phrasing.
The notes you selected, the project you're in, the article you clipped, the examples in your voice - these usually carry more signal than whatever sentence you manage to type. In a good interface, selecting the material is most of the asking.
What to build.
Start AI from a selection: the open document, the highlighted rows, the current project. Offer actions to pick from - summarize this, compare these, draft a reply - instead of an empty rectangle. Keep prompts that worked around for rerunning. And when the user does face the box, offer to write the prompt for them: a rough request plus their context is enough for the model to draft a better ask than most people will type. The blank box can stay as the advanced option. It just shouldn't be the first thing a new user sees.