Yes, but at level 11, and using the Increased Durability augment, the dragon could have no more than 8 HD. A 8 HD gold dragon (the strongest of the metallics) is a wyrmling. Boost its HP by 25%, and it comes to about 85 HP total on a wyrmling gold dragon. A CR 5 critter. I think the problem is something that bugged me the whole time I was putting the text together, and that's conveying the concepts. The augmentations are added to the HD total of the creature you summon. Therefore a 8HD creature with a 3HD augment, total for a 11HD creature.
You might want to read the Art of Summoning entry a little closer. As indicated in the text, and the chart, there are only certain creature types the summoner can choose from.