I was able to get this script to work as a tweetbot by adding the following line at the top.
on :TEXT:!tweet:*: if ($len($2-) >= 110) { /notice $nick The tweet is too long at $len($2-) characters please shorten to 110 characters also try www.goo.gl to shorten the url | halt } | /quick_update $nick - $2- | /notice $nick Your tweet is being posted $len($2-)
My if then/else doesn't quite work right but it does the right check for me by either sending them a message if the tweet is too long or just posting it.