Keywords, tags.... it can also depend on how you're searching and how FAA catalogs them. Basically, whatever you can do to help others find your shots is key. Case in point is this one
which has Savannah in the title, but not in the keywords. Nor is Georgia in the keywords. Google may find Savannah in the caption, but FAA typically will not. I'd also put in a common mispelling of Savanah in the keywords, one n. Put "town hall" in the keywords as well as lamp post and your own name. You get 500 characters, might as well use more than 10%.