I really really missed this option at vbulletin and had to use mod for this function. Right now i am looking forward to move from vb 3 to xenforo and dont want to use mods again with it. I think, there are a lot of times when thread description will be useful. For example, when a thread about a movie or a music band etc. we can simply put its name in thread name and in description we can add country of origin, style, genre and etc. It helps users to avoid threads they are not inetersted in and to find threads they want to check out. And i think, making this function optional will satisfy those who doesnt need description. But i believe, a lot of people would like to see it at their forums.
PS: i do apologize if this is duplicate thread, i do searched but found nothing about thread descriptions.