Most people sight read, It takes no longer to read a word then to read an individual letter. So always use meaningful names. Do they have to be complete 7 word descriptions, no but they need to be longer enough to understand.
I could accept add_loc(name, coord), as they are long enough I can tell what they are. In add_loc(n, x, y), I would object to 'n' instead of name. I could live with X and Y as these are the accepted names of coordinates.
For someone not familiar with coordinate systems I could see where add_location(name, coordinates) would be more meaningful.
When in doubt, use longer names.
