The dwarf's answers are short and too the point. But you get the sense that this is a personality trait and not any attempt to withhold information.
"How many vampire followers does Strahd have? List the names of the ones you've assocaited with, seen and heard of. Do they all live at the castle?"
"I don't associate with many. Just Kavan the Grim. You just staked him. Well, and spawn he's created. Those never last long. Strahd has numerous spies across the land. With four legs or wings. I met Sasha once or twice but I haven't seen her in a good long time. No vamps live outside the castle. I would know."
"Do you know of any vampires or Strahd's minion's that live outside the castle?" "Where is their location?" "What other allies does Strahd have beyond his vampires and their minions?"
"No vamps, I said. But lots of minions. The witches of Lysaga hill. The Drowned Lady lives in the Ivlis March and she is surrounded by so many things that want to kill you but they are natural and do not serve any master but their own nature. The vistani downstream at the Tser Pool. At any given time, there are other mindless tools loose in the woods. Shambling dead at the like. They have no home and move until the decay or are destroyed."
"What is the function of the sun medallion wore by the vampire we slew?"
"No idea. I didn't give it to him."
"Have you been to Castle Ravenloft? Can you draw of map of the places you've been?"
"Never been inside. No desire to be inside... anything."
"How does Strahd defend his castle?" What creatures and monsters roam the halls?"
"Sorry. No help there."
"Do you know what happened to the Burgeomaster's daughter Ireena?"
"Who? I know I haven't hunted her."
"Have you ever heard of Fanes or special places that give Strahd power?"
"You mean the three holy groves? Never knew they gave power to Strahd but I ain't surprised. They hum with the power of the hunt, if you listen to it. Lysaga Hill, Ivlis March and the Svalich Woods."
“How does Strahd normally deal with his enemies?” Why did he send you to attack us?”
The dwarf looks at you with a quizzical look, "To kill you. What other reason is there? He doesn't bother me much. Let's me hunt. But when he calls, it's best to obey. Kavan stopped by my cave and said Strahd needed my skills. He'll either use you or kill you. Same as he does to us all. If it's all the same, I don't need no last meal. And I don't want to be buried. Just leave me out where my friends can get at me. Though I would call it a mercy if you can ensure Strahd won't use me as a puppet."