The word tov would best be translated with the word "functional". When looked at his handiwork he did not see that it was "good", he saw that it was functional, kind of like a well oiled and tuned machine.
In contrast to this word is the Hebrew word "ra". These two words, tov and ra are used for the tree of the knowledge of "good" and "evil". While "ra" is often translated as "evil" it is best translated as "dysfunctional".
If you have enjoyed this perspective, may I recommend Jeff's website? It is an absolute treasure trove of wonderfulness. http://www.ancient-hebrew.org