Testfor dropped items minecraft
Solution 1:
You closed the selector's parameters and opened them again, breaking selector syntax. You need to include all parameters within the same set of square brackets. You've also not completely closed the NBT data, just missing a final closing curly bracket. Fixed:
/testfor @e[x=445,y=88,z=216,r=3,type=Item] {Item:{id:"minecraft:egg"}}