on mine:
if line 1 of lore of player's tool contains "%{ilosc.kilof}%/100":
remove 1 from {ilosc.kilof}
set line 1 of lore of player's tool to "%{ilosc.kilof}%/100"
if {ilosc.kilof} is less than 1:
set player's tool to air
przerobilem z mojego, nie sprawdzalem czy dziala, mam nadzieje ze kilof sobie sam zrespisz