When it comes to course descriptions, the more information you can provide about each class the better, as long as you don't go over 1 page of information. That's why I often suggest that each description includes 3 main ingredients.
1. Write a paragraph about what you did
2. Make a list of what you used
3. Describe how you graded.
Within those main ingredients, there are a lot of different ways to give information about your class. Some parents go into great detail on each of these, and other's don't.
When you are considering how much information to give about grades, some parents will give an overview, like this:
Other parents will simply provide a conclusion with the grade that was ultimately earned, like this:
Final Grade for Algebra: 94% = A
Another parent might decide to give a blend of overview information and final grade:
Tests and Exams 60%, Classwork and Homework 40%.
Final Grade for Algebra 1 94% overall for 4.0
And then there are other parents (like me) who provide a grading table with individual grades and scores provided for each test, quiz, or paper.
When I wrote course descriptions, I tried to provide every possible individual grade that I could within a grading table. I wasn't perfect though. There are some tests and quizzes and lab reports that I simply lost, and then I would either leave those blank or not mention that they were missing - as if I'd intentionally not used that test on purpose.
Provide course descriptions any way that you can - short or long, whatever works. I think any way that you do it is fine, and the more information you can provide the better.