To be fair that's the official docstring for defn. When you browse over to the docs for def (http://clojuredocs.org/clojure_core/clojure.core/def) the official docstring tells you to go look it up on clojure.org:

    Please see http://clojure.org/special_forms#def

I believe this odd behavior is because Clojure's special forms are written in java and thus don't have easily parsed .clj source for the automatic clojure doc search tools.