I want a tool that cleans up my bookmarks. I'll often bookmark a page to look at it later, but then never get back to it or forget I bookmarked it. After a few years of using Chrome, I've got a crapload of bookmark bloat. Here's what I'm looking for in such a tool (I might try to build this unless there's something out there already that does this):

* Surface bookmarks I haven't visited in the past N days/months, give me the option to delete them

* Identify groups of bookmarks that are similar (share most of the URL path or one page links to the other) or duplicates.

* Suggest folders to place the bookmarks in based upon what Google knows about the websites (Sports-related, WebDev-related, etc), and/or time (I bookmarked five pages about similar topics on the same day, it's probably part of research I was doing for something)

* Remove dead links or offer to convert them to the Google-cached version