It searches tags and urls too. I'd like a full body-text search for bookmarked pages or something similar, I'm a hoarder (I actually have a script to archive all my bookmarked pages, via wget, so i can grep them).
Also, https://support.mozilla.org/t5/Basic-Browsing/Awesome-Bar-Se..., last couple of paragraphs site hire to use the modifiers in address-bar search for those who don't know about that.