I don't find this clear:
Left 10 comments with score of 5 or more
I would prefer:
Left 10 comments, each with a score of 5 or more
I think that is rather improbable 5 is the total score of the 10 comments, considering that the badge is a silver badge; that would mean a score of at least 0.5 for each comment.
There is no need to change the description; many of the badge descriptions are intentionally open to more than one interpretation. The reason is that badges should be a surprise, not something you exactly know when you get them. (At least this is the description somebody else used for the badges.)
Jeff Atwood, in A Bevy of New Badges says: