A phrase used to denote an activity that appears productive however is neither productive nor fun. Can also denote unproductive behavior.
The phrase originates from northeastern Pennsylvania with an anecdote of children pantomiming their cigarette smoking parents by using tinker toys as opposed to more sensible options, such candy cigarettes.
Ex.: “There were piles of paperwork and tickets to process on his desk, but he spent most of the day smokin' tinker toys.”