It seems that if there are six bullet points, then every single one should be mentioned, although in reality all this may mean nothing for the admissions committee, and even for the student himself. Often, one achievement can dwarf all others.
A purely hypothetical example: there is a student, a physicist who destroys local competitions, in his spare time builds a time machine and compiles on C. But he read in our instructions that it is necessary to mention this and that, and wastes a whole paragraph of already limited page real estate in order to tell how he helped old ladies to cross the street. Of course, volunteering is a good experience, but does it say anything about a real passion for the profession? Words and sentences in a motivation letter are your “nonrenewable resources”, which should be spent only on really significant information.
A real case: a student was applying for a computer science program. In his time he had already launched two startups and in his letter described his apps a little. Then he moved on to the painfully familiar and tired pattern about how he wanted to study and how much he was interested in the chosen field. I asked him to write some more about the difficulties in development and how he had overcome them. This information is not only directly related to the profession, but also demonstrates to the admissions committee that the applicant is able to think critically and has problem-solving skills. He very quickly came up with another half-a-page about how he had troubleshoot various bugs and implemented features. It was a vivid, interesting read and, most importantly, it demonstrated the genuine interest in the profession that could so easily be lost in a series of general statements and cookie-cutter phrases. At the same time, for some reason, he did not consider it to be necessary to write this in the first place, despite the fact that this exact thing matched the profile of his education.
The point of the whole story is that if you have a relevant shtick, then it should be the core of your motivation letter. There is no need to spend valuable space on often mundane and insignificant information in an attempt to tell about everything in the world just because the article says so. As Barbossa said in “The Pirates of the Caribbean”: “The code is more what you’d call “guidelines” than actual rules”. There are general principles, tips, but the final result depends solely on you.