slayer deed

I have 105 tinkering skill and it shows %0 chance of success for slayer deeds even if it says that it erequired 105 tinkering. Why is that?

Can anyone help me figure out a slayer deed? I have one and cant get it to apply to weapons. Not much anywhere on how to use or what kind of weapons must be used.... every weapon type i try get a new excuse why it wont work lol