^The above poster is correct.
Furthermore, the 250-500 word “limit” is not an actual limit; it is simply a guideline. I’ve contacted Common App about this and they assured me that they do not have the software to limit the amount of words on thousands of uploaded documents.
That said, I wouldn’t advise going over 800; 500-750 at MOST seems like a good range, from what I’ve read, heard, and experienced.