
DHAnubis |

Natural attacks are done at your full to hit bonus if they are primary attacks, at a -5 (usually) if secondary. As claws are primary natural attacks, you would get an attack roll with both at your normal to hit. If, however, you were to attack with a manufactured weapon with one hand, and claw attack with the other, the weapon would be at normal to hit bonuses, and the claw would be at -5 to hit and deal .5 strength.

Scott Wilhelm |
Further, adding more natural attacks will not interfere with your claws. A Tengu with Claws can make 2 claw and 1 bite attack with no penalty. If she takes a level in White-Haired-Witch, she also gets a hair attack, still at no penalty. If she acquires a Mammoth Helm, then she gets a Gore Attack, all at no penalty. If she puts on a Tentacle Cloak, the tentacles get a -5 because they are secondary, but the rest are still all primary, and no penalty. Hello, WARPRIEST!
If you only have 1 natural attack, it is primary even if it is normally secondary. Meaning that tail slaps are normally secondary natural attacks, but if you are an anklyosaurus, that tail is the only attack you have, so it's primary. Likewise, most Alchemists who take the Tentacle Discovery do not take the -5/.5St penalty as long as they don't have any other natural attacks, and as long as they don't use a manufactured weapon.
The Muliattack Feat will reduce your secondary natural attack penalty from -5 to -2.