Not to say your advice is bad, but I think in many cases course descriptions are so short and vague that they won't tell you much of use. Sometimes there can be useful info in there but reading through every course description could be pretty mind-numbing. What's more informative is if you can actually get detailed course info like a reading list, assignments, etc. Unfortunately these often aren't publicly available, but professors may share them if you ask via email and explain your situation.

I do agree that looking at the required courses and degree plan is important.