The affectsState element is not equivalent to the definition of idempotent as defined at the given link (https://tools.ietf.org/html/rfc7231#section-4.2.2) The link specifically says that PUT and DELETE are idempotent operations, but those would clearly affect state.

It's not clear why there is a reference to idempotent here and whether that's important. Consider either adding language to clarify why "idempotent" is important in this context, or removing the reference to idempotent altogether.

Also, the wording does not flow, there is an "= false" at the end of the first sentence that does not make sense.

Also, there is a missing parentheses at the end of the link.