Final answer:
MGRS coordinates require more detail to specify a square size precisely; without additional digits in the '8S AE 13' coordinate, we cannot determine the exact size of the square.
Step-by-step explanation:
The Military Grid Reference System (MGRS) provides a way to break down the Earth's surface into a series of squares for easy referencing and navigation. A coordinate like 8S AE 13 doesn't fully specify a unique square because it lacks the necessary detail; normally, MGRS coordinates are presented with grid zone designators and then easting and northing numerical identifiers. However, if we assume this coordinate is meant to indicate a 1-meter resolution, given that each additional digit represents a tenfold increase in precision, the square size would be 1 meter. If the coordinate lacks significant digits, it's impossible to determine the exact square size without further information.