Below are some GREAT resources for the teacher that wants a rubric attached to an assignment. It is possible to grade a google form with essay type questions in it's current form. This blog post explains how: http://www.controlaltachieve.com/2016/10/extended-response-forms.html
For other functionality, Doctopus is one of my favorite rubric tools. (attaches a rubric to a student google doc seamlessly with Google Classroom. Also has functionality for one to record audio feedback that gets linked to student work. The setup is somewhat difficult but once you get the hang of it, it's pretty awesome!) bit.ly/doctopus-goobric
OrangeSlice is a Google Doc add-on that is a rubric builder too. I liked it's ease of setup, and options for holistic (avg value) versus analytical (%) grades. It also can track growth of a student.
JoeZoo is another Google Doc add-on that in my opinion was a little easier to setup than Doctopus. It has a cool Monkey Grader option that evaluates all the mechanical/fluency/spelling errors in a document, and provides feedback to the student on how to correct them.