Pretty solid signing for the minimum. The Spurs obviously want to be compe ive this coming season, as evident by calling Belinelli at 12:01, so Cunningham fits pretty well with their win-now priorities without sacrificing salary cap room in future campaigns.
My bet is that Cunningham plays strictly power forward for the Spurs. He was never really quick enough to hang with the faster small forwards to begin with. At the wrong side of 30, that'll be be even moreso the case. Adding a somewhat reliable three-point shot makes it possible to picture him as an Horry-type player. At PF, he's also a really good pick-and-roll defender. All in all, he can soak up minutes at PF next to Aldridge or Gasol at C without hurting the Spurs. Not too bad for the minimum.
I remember the Spurs were supposedly interested in him a few years ago but a lot of teams backed off when he got hit with domestic violence charges. It turned out that
she probably exaggerated or completely made it up.