Indra suggests glanceability, from Lorcan Dempsey's blog. Like any useful neologism it has already leapt well beyond its origins way back in 2006 in an article on glanceable design by Matthews, Forlizzi and Rohrbach. New words of value, like this one, spread quickly, and their meanings start to evolve almost immediately.
The word is defined by Tony Hirst as "the ability to look at a screen and capture the information you require at a glance." So glanceability is VERY important. Lorcan also refers to Matthews et al who define the word as enabling "users to understand information with low cognitive effort", and further: "Glanceability refers to how quickly and easily the visual design conveys information after the user is paying attention to the display."
For librarians and their friends, Lorcan's library-specific conclusion is predictable but important - library website "require quite a bit of cognitive effort to figure out what is available where as they present a thin guiding layer wrapped around a resource fragmented by legacy categories." Not glanceable at all, really.