I think that whether or not to include a long description or narrative depends on the type of photography used.
Documentary and journalism usually requires a full narrative to give the image context. Without text, an image viewer unfamilliar with the subject has no idea what is going on in the photo. The description must explain why the subject is important. Sometimes this will be a detailed explanation while other images may only need a title or a date and location.
Artistic photography, in my opinion, should not require a description or even a title. It should stand on its own, and should communicate a simple feeling or a more complex idea without need for a description. In fact I think that an image with an interpretive title is more of a gimmik than true art. A title or description may add some context to a peice of art, but it should not be required to make it artistic.
Now, I'm not saying that documentary and journalism cannot be artistic. But I think the distinction must be made between an image that communicates on its own verses an image that has little value without a description or title.