We regularly have the tensioner checked at our local Firestone, but something went wrong with it shortly after our last CVI in November. The engine started to make a faint, raspy noise about a month later, then the tensioner failed just over a month after that, after about 2,000 miles. I thought the weird sound could wait until our next oil change but boy, was I wrong. The part broke, which then led to damage to the serpentine belt & caused our coolant to boil over since the belt was no longer powering all the car'* accessory systems. We had to get the car towed home, and the towing & repair (which we needed done quickly) cost over $500. Ouch. Could this part replacement have been detected earlier by our mechanics? The sound was so faint I ignored it until the tensioner broke & I immediately assumed that was where the sound was coming from.

Welcome to the forum Kendall.
For better visibility and replies, I have created a new thread for you.
Sorry to hear your tensioner failed.
How many miles were on the car when the tensioner packed it in?
I would normally recommend that you replace the tensioner any time they become noisy or present some bearing movement. (slight wobble may be seen) Movement may be felt when you try to pull up /down on pulley.
Mileage does play a role here as well. I normally change mine every 100,000 miles just to be on the safe side, and include a new belt at that time.
By your description of the sound being so faint, unless an auto stethoscope was used on the bearing, it may have been difficult to detect. However removing the belt and checking for play and spinning it, may have givin some hints, that it was due for a change.