If you open a note you can also add to the note with a comment which the student will then see.
You can can use this to mark an answer, feedback or give wider guidance or detail.
You might as an example, for homework, ask all students to write a paragraph on a topic using four of the keywords chosen from the keywords element. They can then add this as a note below the keywords step for you to then visit and mark.
You may want to put your comments in red by changing the font colour.
Both you and your student can print the note or download it as a word file.