It might be required for you to import the package if you encounter any issues (like casting an Array), so better be safe than sorry and add the import at the very top of the file.

ZenScript
 Copy
import crafttweaker.api.loot.LootContext;

Name	Type	Has Getter	Has Setter
Name attackingEntity	Type Entity?	Has Getter true	Has Setter false
Name blockEntity	Type BlockEntity?	Has Getter true	Has Setter false
Name blockState	Type BlockState?	Has Getter true	Has Setter false
Name damageSource	Type DamageSource?	Has Getter true	Has Setter false
Name directAttackingEntity	Type Entity?	Has Getter true	Has Setter false
Name explosionRadius	Type float	Has Getter true	Has Setter false
Name lastDamagePlayer	Type Player?	Has Getter true	Has Setter false
Name level	Type ServerLevel	Has Getter true	Has Setter false
Name luck	Type float	Has Getter true	Has Setter false
Name origin	Type Vec3?	Has Getter true	Has Setter false
Name random	Type RandomSource	Has Getter true	Has Setter false
Name thisEntity	Type Entity?	Has Getter true	Has Setter false
Name tool	Type IItemStack	Has Getter true	Has Setter false