Recommendation letters from superiors should have at least 6 paragraphs in my opinion.
The first is for your recommender to introduce him/herself and her relation to you, and the last is to express hope for you and to recommend the school's consideration for you.
The middle paragraphs are in chronological order where each paragraph will exhibit a certain skillset of you. First will be how the recommender got to know you. Second, will be about your academics i.e. how good at learning you are, how much logical thinking you have and what role you played, your contributions, etc. Third will be that you have undergone training or have experience and is liberal enough to take all criticism as a basis for growth. The last paragraph should be on your work, your independence, and leadership skills.
Hope this helped!