The assemble_per_record MCP tool performs a mail merge: one document per record of a JSON array — a letter per customer, a certificate per attendee — named by a record field, with failed records listed instead of stopping the run....The assemble_per_record MCP tool performs a mail merge: one document per record of a JSON array — a letter per customer, a certificate per attendee — named by a record field, with failed records listed instead of stopping the run.