Agree the field dictionary first
Start with the fields the business actually uses. For each one, define its meaning, format, source expectation, and reviewer. “Renewal date” is too ambiguous if the operating process needs both an option exercise deadline and the beginning of a renewal term.
Separate dates stated directly from dates calculated under an approved rule. A calculated date needs the input values and the rule version that produced it. The application should not present a model-generated calculation as a direct quotation from the lease.
Keep monetary fields similarly explicit. A base amount, an escalation rule, a deposit, and a reimbursement obligation should not share a generic “rent” field. Units, currency, frequency, and effective periods belong in the schema.
I would begin with a limited field set that reviewers can consistently interpret. Expanding the extraction target before agreeing definitions makes apparent coverage increase while review quality falls.