This is already a softer statement than the rule proclaimed in the article ("not many" vs "none"). And if you have to do something unusual due to limitations (

This is already a softer statement than the rule proclaimed in the article ("not many" vs "none"). And if you have to do something unusual due to limitations (say, a bug in a 3rd-party library) in your code I don't want to know about that when reading the method's documentation (what you refer to as "summary") to be able to use your code. I want to be bothered with it when I have to read its implementation because I have to fix some bug in it.