You can seamlessly use the Kami tools in Canvas Speed Grader to provide feedback, guidance and instructions for the students alongside their grades.
Once the assignment is pushed out and the students have completed their work, you can open the files through the Canvas Speed Grader, and start Grading:
Open the Assignments option from the Course Section inside Canvas.
Select and click the assignment you wish to grade.
Select the Speed Grader from the top right of the page
Once you have selected the Speed Grader, Canvas will open the grading viewer. The assignment file will load in a Kami window inside of the Grader.
Once the file has loaded, you can use all of the Kami tools to annotate the student's work with any comments, notes, instructions or information you want to add.
Once you have marked up the document, you can add a grade and any other comments. That grade and the annotations will be automatically returned to the student.
You can use the arrows on either side of the student name at the top-right of the screen to cycle between the submitted files.