A Mechanic reports about his efforts to locate his Leatherman tool after servicing the #2 engine oil on an A319 at their hangar ramp area. The A319 had already been taxied to the terminal when he found his Leatherman in pieces on the taxiway. At the gate; he noticed that FOD damage had occurred to the engine inlet and fan blades.

Narrative

After completing my entries in the logbook for an A319 aircraft; I went back outside to check the oil on #2 engine at XA:05 am. I looked at the [oil] sight glass and saw it was low and put two quarts of oil in the engine. I opened the oil cans in front of the inlet. Then came back inside the hangar to put my tools away. That's when I noticed I misplaced my Leatherman tool. I went to the Lead [Mechanic] on duty and asked did the aircraft leave? He told me that it was holding in the alleyway to taxi to the gate. I went and did a FOD walk and found no Leatherman. When I couldn't find my Leatherman; I remembered being in front of the engine. So I went to check it out and the plane was pushed away. Thats when I thought the worst. I asked the Lead to call the person taxiing the A319 aircraft to see if I left my Leatherman on the plane. The Lead did and the gentleman said he had not seen it. About XA:20am; the Taxi Crew came back and I asked face to face did they see my tool; both gentlemen said no. I asked one of the gentlemen to please take me to the gate were the aircraft would be.As we drove I saw my Leatherman on the alleyway. The tool was in pieces; I picked up what I could; then continued to the gate. We arrived at the Terminal gate at XA:30 am; there I saw inlet damage as well as fan blade damage. I called the Lead on duty at XA:40 am to tell him the issue. He told me to come back to the hangar and he took care of the rest.I was complacent and had bad communication with my peers. Let everyone that I work with know what was going on all the time. Ask my peers to take a double-look just to be safe.