On 01/02/2010 in "Secrets of the Alchemist Dar", in "Game over - Petition for a solution", I posted:

"I believe the dragon in ATT represents Pook's hidden courage and loyalty, notable qualities of oriental dragons and perhaps some western ones. Several apparent clues in the book support this interpretation.
I assume this is also true for SOTAD, perhaps in addition to pale drophidians, but I have never looked closely there for support for either interpretation."

I still believe this. I think courage is the primary quality intended, but loyalty fits well along with it.