Hi ,
I tried creating a last comment script which will return the last comment added in the issue.
I have added a scripted field to get the details , but in that when i tag people in the comment , We are getting atlassian id instead of name.

Code :
def comments = issue.fields.comment.comments;
def lastComment = comments.last();
def lastCommentBody = lastComment ? lastComment.body : "";
return lastCommentBody as String;