Important note: all examples follow aTbRef naming conventions.
Action code allows commenting and adding comments to a function is a good idea. The scope and depth of notes is a matter of personal taste, but if making a library of functions for other people, it is a good idea to explain the purpose of the function and the data types of argument and return values.
To make it easier to see the function code without scrolling, one approach is to put a comment at the start of the function indicating the main detail is at the bottom of the function.
Next: Comments in functions