Length matters buddy. To be honest with you, length is an issue that most of the students are bothered about. Papers can to any kind of teacher. Some like lengthy explanations other short and precise. Even you can be penalized for writing more if your paper is checked by the mentality of short and precise writing lover.
so i would suggest you should then write more but there should be quality in ti. if you think that there is no quality the move to the next question.
Best of Luck.