Honestly, I wouldn't do so. Tim's fastballs have been decreasing in velocity over the years. In addition, the San Francisco Giants (personally) aren't a run supporting team for him.
On the other hand, Braves have a similar lineup. The key to my reason to not trade would be with Jordan Zimmerman. He is coming back from Tommy John and has pitched a stellar season last year. He is also part of the Nationals, a growing team with each year to come. Plus, Zimmerman is pretty young.