This may have already been covered so sorry if this is a repeat.
I am not quite sure I understand traits.  For instance I see that there are a specific rules for things like PIERCING.  But what about others like charming, or ancient mind?  I don't see rulings.  Is this because, and I am assuming so, that they are descriptors and it's up to gm/fiction to describe what they mean and do. Someone please help.

Thanks in advance.

John