This is the just minimum requirement for the post to be counted not a fixed number of words. Moreover I did not said that you did wrong I just said that you can enhance it more while exploring the questions more. You can add more depth in the answers by covering more aspects. You have gotten great marks because of your work there are also students who just got 4 marks so I evaluate the quality and hard work put into the post. You are still better than many others. It is not just about getting marks it is a learning program where you will learn if you go more in depth details and research.