A fractional jet pilot reported they shut down one engine on descent due to low oil pressure. After landing; upon inspection found oil leaking from the right engine.

Narrative

We were flying from ZZZ1 to ZZZ at FL190. As we were about to descend on the ZZZZZ arrival; we received a red CAS message; R ENG OIL PRESS LOW;" followed by the aural alarm. As I was retrieving the QRH; we were cleared to descend via the arrival. We began our descent; and I read out the checklist; which called for the right engine to be shut down. We told ATC about our situation and continued with the associated checklists. As we were reaching the final altitude on the arrival; ATC gave [priority handling] to us. We coordinated with the tower and emergency personnel about the situation; asking them to check the right engine upon landing. An emergency vehicle would follow us on the runway. We landed on runway XXL and taxied back to the FBO; where we entered and were met with the fire engine and emergency personnel. Upon a visual examination of the engine; we could see a large quantity of oil along the nacelle and the back fuselage of the airplane. The oil continued leaking on the ramp. Cause: I believe the improper installation of the oil cap on the right engine was the reason for this. The oil cap was locked down; but there was a chain connected to the oil cap to keep it from falling when oil was being replaced that was installed inside the oil reservoir neck and attached from the inside of the oil reservoir neck to the outside cap. This did not seem to allow a tight seal for the oil cap when in the down and locked position. However; I am not privy to how the cap was before the maintenance or in the mind of the maintenance official; so I'm unsure exactly the cause of the oil leak.Suggestion: If the oil cap chain was improperly installed; ensuring that maintenance personnel do not install it that way would be the primary step in preventing this event from occurring again. A secondary step would be to have pilots ensure that the chain is not in the way of the seal during oil inspection."