I can't keep my hand off the cookie jar. Its just too tempting to eating the sugary goodies all day.
I feel you. Is your jar glass or ceramic?
Its glass, so that I can see how many are left before I need to refill. I would hate to run out of cookies. 
What kind of cookies do you usually have in your jar? Cookie jars can also be used to store candy or dog treats.
I usually have chocolate chip cookies for myself and a separate jar for dog treats, as you said. 
In the United Kingdom they are called biscuit barrels which is kinda catchy
Biscuit barrels?! You can always trust our English friends to come up with the most absurd nick names.
Yep! If the jar is tinplate, they call it a biscuit tin.