This is quite true and one of the reasons I hate auto-doc comments. If a function tells me that an input is an integer there's no reason to repeat that information in the header above the function unless that information is then being parsed to produce a more readable form of documentation (i.e. as JavaDoc was originally used). Additionally I personally, though I am happy to concede that it may benefit some people, loathe "$documentId The ID of a Document" style comments. If you are adding more information above and beyond what is relevant from code - especially if that information relates to why you chose this approach over a different one - that is useful information.

Documentation in the form of project planning documents, SOWs, data diagrams etc... - that stuff is always quite valuable, especially since it comes with an understanding that it was valid at a certain point in time (and may no longer be valid) but belies underlying decisions in how things were built and why.