Is this a good add for gumtree?

[Asker]

I'm posting an add on gumtree to offer help to people in exchange for money. This is what I have written down. "I'm a hard working 16 year old looking for a job to keep me busy over the summer. It can be anything from walking your dog(s) daily or to Help with building/painting fences. If you're in need of help putting together a shed or need a hand clearing out your back garden, contact me and I will be happy to help. I have no set prices, so you tell me what you're willing to pay beforehand, and if the help I give is not good then you will not need to pay"

Is this good enough? could you help me make it better?

[jack smith]

gumtree is good classified site of Australia.