You're not in the bestest part of town or anything but it isn't horrible. You'e on the opposite of Civic Center from the Tenderloin. Keep in mind, though, that the Tenderloin really isn't that bad except maybe in the middle of the night. During the day it is fine, if obvious about its seedier side. I've been in the Tenderloin late at night many times and never felt endangered.
Sixth and Mission, however...
Here's
a map of the area.