This goes along with the mini assignment I give them on writing OPINION paragraphs.
It's a rubric that makes making easy!
It can easily be tweaked to fit what you need, but this includes a mark for:
-arguments and examples
It has a breakdown of what's included in each one of those topics, for a total mark out of 30. There's also space for comments at the bottom.
NOTE - there's an opinion paragraph assignment in my shop as well!