Bad map description, need help figuring out

So I’m all done with my map, and all that is left to do is upload it to my share. Unfortunately I keep getting “The custom description for this file is not allowed on xbox live. You must change it yadda yadda”

My description:

Deep underground is an Arena built on a Foundation of Blood and Bones. 2 Teams, 6-12 Players, TS, KOTH, CTF Compatible

I’ve been trying different combinations of synonyms for each of those words and I’m still getting the message. So help would be much appreciated