I question the accuracy of this tool

Just one of those things you have to try, like emu burgers at Sunfest.
Since the embed code for the graphic includes a link [removed] to a site offering usurious loans, and a hotlink [also removed] for the image, it is a form of spam, isn't it? But just too tasty to pass by. Would they even bother to check reading level, whatever is meant by that. If The Volokh Conspiracy is junior-high level and Rand Simberg is high-school level; and bloggers at those sites are smarter than I am (they are, you know); then maybe I ought to try writing a bit differently?

What? And compromise my artistic integrity? They don't pay me enough for that!

Update: Further research on this at The Periodic Table.