Calling all Sloan MIT Applicants (2016 Intake) Class of 2018!!

Resume contains bullet points and one liners. I am assuming whatever you have provided in the resume won't contain the whole situation and your thought process. Considering that MIT's interview will be mostly behavioral, what they need to know is your behavior and actions during those situations that led to the result (part of your resume). So I think you can focus on most of the things already present in your resume, as that will only be 10% of your whole response. The main story, I assume, won't be part of your resume.

But you should avoid whatever you have mentioned in the mandatory question and the optional question, if applicable as that might contain all the details.