Cessna 206 pilot reported an engine malfunction during descent. The pilot maneuvered towards an alternate airport. The engine failed on landing rollout and aircraft towed to the ramp.

Narrative

During descent into ZZZ; we experienced a momentary loss of engine power. The engine returned to normal power after two seconds. After about five seconds the engine struggled to maintain power again. I will turn left towards ZZZ1 and begin troubleshooting. Selecting the left tank with the fuel pump turned on restarted the engine. We will continue to hold altitude; avoid any additional engine changes or configuration changes until overhead ZZZ1. We will commence an idle descent with a running enging to touchdown. On rollout; the engine will fail during the landing rollout. An attempted start with the start side of the electric fuel pump will show no fuel flow. Only with the side of the electric pump will the engine show fuel flow; but will not start. Aircraft is towed to the ramp and secured.A normal preflight was conducted that showed full tanks. This concurred with the fuel totalizer. A post-flight inspection will show 25gal in the left tank; and dry in thw right tank. We will use a timer to switch tanks during the 1.7hr flight. A closer inspection of the total fuel in each tank as calculated during the tank switches could've given us earlier insight into a problem and allowed troubleshooting. Both tanks had their fuel caps on during a post-flight inspection; so the other potential was an incorrect reading of each tank during preflight. I checked the dipstick twice but this is still a possibility. The early decision to go direct to ZZZ1 contributed to us having options had the engine not restarted. Crew coordination with checklist usage was delayed but was completed before the descent from our altitude.