WHY DOESN'T MY COMMAND WORK

[u/ledzik_precly]

Im trying to make it so if a player has 1 durability left on their pickaxe they get a broken variant of that tool and can cheaply repair it in a crafting table, I wanted to test out this system with command blocks but somehow they only work when I type them in chat, PLEASE HELP IM LOSING MY MIND. Also ik there is a snowball as item needed but thats a place holder

Repeating | Always Active

execute if entity at s[nbt={SelectedItem:{id:"minecraft:snowball",count:1}}] run scoreboard players set at s GiveDiamondDrillBase 1

Repeating | Always Active

execute if score at a[limit=1] GiveDiamondDrillBase matches 1 run give at s minecraft:diamond

Chain on top of preavious one | Always Active

execute if score at a[limit=1] GiveDiamondDrillBase matches 1 run scoreboard players set at s GiveDiamondDrillBase 0

[u/Kecske_gamer]

[@s] refers to the entity running the command. In your case the command block is attempting to refer to itself instead of any player