This collection includes the 6th, 7th, and 8th grade version of a detailed 4-point rubric that assesses three Common Core Standards:
W.6/7/8.1 (Write and support an argument or claim)
W.6/7/8.5 (Develop and strengthen writing)
W.6/7/8.9 (Draw evidence from literary or informational texts)
The rubrics also include a goal setting component, for teachers to set with students before writing instruction. There is a space for teacher comments, for you to do while you assess or score the piece, as well as two prompts for students to fill out and reflect on their performance.
You also get a correlating Class Report sheet.
In case you only need one grade level's version, I sell these separately as well.