How a specific does a patent have to be?

Your patent application specification disclosure must be specific, as in complete, accurate, and thorough - you need to describe what you have, how it works, maybe even why it works the way it does, why other similar devices do not work or do not work as well. The claims, however, is what define your patent and your patent protection, so you try to tailor your claims to be different enough from known patents or other publications which make the claims patentably distinct - you will probably need to consult a patent professional to discuss this and to determine your level of patentability. And with respect to the multiple patents for multiple smart phones, each patent contains or should contain one claimed feature which has not been publicly disclosed and is not present within, for example, any of the patents that preceded it.