Creating a Gmail Agent to Automate Payment Request Processing

I'm struggling to create a gmail sorting agent that takes payment request emails and forwards them with the attachment to a different Accounts Payable email. i also want it to review the details of the attachment and the body of the email to ensure all the payment details like ACH info and details on what we're paying for are. the gmail tools have a hard time processing the attachments and the download attachment tool needs me to re-name the attachments and do a bunch of extra stuff i'm hoping i can avoid. Any solves for this?