The mower deck belt on my Toro 13-38 XL riding mower is slipping. Can I adjust the tension pulley to take up some of the slack?

Hi,
It is kind of necessary to have the 5 digit model number. Toro does have some of the finest online manuals available so that we "speak on the same page." Look for the white or silver tag with model and serial numbers on it; often under the hood.
Peace,
Clarke