JoeZoo Express is a great Google Docs Add-on that lets you insert canned comments into your students' documents. You can use JoeZoo's pre-made comments or you can create a menu of your own comments to add to documents. Once you've created comments you can use them over and over again on any documents that your students share with you. Over time use JoeZoo Express can save you lots of time when you're giving your students feedback on their work.
JoeZoo Express is more than just a commenting tool. You can also use it to create rubrics for scoring your students' work. Much like the commenting feature of JoeZoo Express you can use your rubrics while looking a student's document. The following video shows you how to create a rubric in JoeZoo Express.
JoeZoo Express is the Google Docs Add-on offered by the company named JoeZoo. There is also a JoeZoo app that you can distribute domain-wide through G Suite for Education (I hate that name compared to Google Apps for Education). The JoeZoo app includes tools for students to use for peer review and includes tools for teachers to share rubrics.