If this minor shake is felt worse as you accelerate, misfire. l felt it quite well, when it was happening to me. My engine was a 4 cylinder. Will drink fuel like crazy! Before you go to any expense, make sure your wires are secure on the plugs. Others here will have more ideas. You're welcome.
The minor shakes on a 2006 Jeep Commander Anniversary edition could be due to unbalanced wheels. I would advice you to take vehicle and have it diagnosed by an authorized Jeep Service expert to determine the exact cause of the Jeep Commander to shake while idling and fix the issue.
Broken motor mounts or maybe broken transmission mounts. any lights on on the dashboard? vacuum leaks and such would cause the cars computer to send a code and your dash warning light would come on. a motor mount would not show up on a dash board light.