Can you have prompt builder check against a document.

Prompt Builder AI skill doesn't support direct document reference - it works with text input that you provide directly in the prompt.
However, Enterprise Copilot does support exactly what you're describing through "knowledge sets" where you can upload policy documents and then ask questions referencing those documents.

https://docs.appian.com/suite/help/24.3/user-copilot.html
https://appian.com/blog/2024/upgrade-processes-new-generative-ai-skills

Prompt builder cannot extract data from a document.

You can have other AI skills like extraction from document to extract policy data from document (in case you have variety of documents dynamically uploaded) and then use prompt builder to validate the data in json against policies extracted from previous AI skills.Give it a try!