The First Mistake in Documentation

From the Java 6 docs for Buffer:

capacity

public final int capacity()

Returns this buffer's capacity.

Returns:

The capacity of this buffer

And no, it's not an isolated case. It's followed by "position - return this buffer's position"

I don't know how many times I've seen stuff like this. Why do people write this kind of thing? They must know it's useless. Is it just because they are "required" to write documentation so they fulfill the letter of their requirements? Maybe IDE's are too good at generating boilerplate which then gets left as generated.

Comments like "x = x + 1 // add one to x" are a similar phenomenon