Just in case @Impractical Horsewoman doesn’t get back to explain herself in a timely manner, I’ll hazard a guess that she meant “The description by the OP” instead of what she posted, “The description of the OP”.
In this context, it’s possible to read “of” and “by” as having the same meaning. That is, as referring to the OP’s statement about the BO/BM. It’s just that in that sentence, reading “of” as referring to the OP’s statement, not the OP herself, not common English usage.