Adding a description on a blank page should be more obvious

[LeBenLeBen]

On a page that doesn’t have any text field, the "description" part of the seo preview is somewhat hidden as you can see on the screenshot below:

By looking at the source, I discovered that I could click on the bottom part of the box to open the description field. I think this should be more obvious with a placholder text like "Click to add a description…"