You can tell it, in the custom instructions setting, to not be conversational. Try telling it to 'be direct, succinct, detailed and accurate in all responses'. 'Avoid conversational or personality laced tones in all responses' might work too, though I haven't tried that one. If you look around there are some great custom instructions prompts out there that will help get you were you want to be. Note, those prompts may turn down it's creativity, so you'll want to address that in the instructions as well. It's like building a personality with language. The instructions space is small so learning how compact as much instruction in with language can be challenging.

Edit: A typo