Every line of documentation is a line of code and is a liability as it will rot if not maintained. That’s why you should be writing self documenting code as much as possible that’s obviates the need for documentation. But unlike code, stale/wrong doc will not break tests.

Spending 15 hours documenting the code is something no leader should be asking of engineering to do. You should not need to do it. Go back and write better code, one That’s more clear at a glance, easily readable, uses small functions written at a comparable level of abstraction, uses clear, semantically meaningful names.

Before you write a line of documentation, you should ask yourself whether the weird thing you were about to document can be expressed directly in the name of the method of the variable instead. Only once you have exhausted all the options for expressing the concept in code, then, only then, are you allowed to add the line of the documentation regarding it.