You could say "self explanatory". For example, a book with the title "History of Britain" - the title is self explanatory. ( ie it explains itself) My cat is called Fluffy - her name is self explanatory! Is this the context you mean? eta ( edited to add) : Alternatively, you might say "it speaks for itself" - The hotel's good reputation speaks for itself, the facts speak for themselves ( ie, no further explanation is needed)

you can say it talks about itself, or it describes itself