In the book text, Fearbreaker is actually a little too big for Andy, and is too small for Baine. Mostly it's a token of friendship, since it's entirely useless to Baine as a weapon. If it didn't represent more than it did, it would probably make a better paperweight for Baine than anything else. He sends it back to Jaina in Tides as a warning that shiz is about to go down.