I have an “External Tool” that gathers feedback on assignments in a course. I am saving the feedback gathered by this "External Tool" of mine on my server. I want to bring this list of feedback by calling the APIs offered by my tool and show the feedback to the instructor. What feature of Canvas should i use to display this list of feedback to the instructor?
Is your "External Tool" an LTI tool?
If so, you could check the role of the user launching it and if they are an instructor, given them an interface to see the feedback.