Adobe Acrobat Sign for Salesforce: Setting Contract, Account, and Contact for a Document

When using AdobeSign in Salesforce and making a call to echosign_dev1__AgreementTemplateProcess to create a new agreement via a custom button, is it possible to specify the account, contact, and contract?

We can pass the master id of the primary record, such as the contract id or account id, and the template id, but I haven't been able to figure out how to specify all three values, though you can set them in the UI that opens up.

For example, this specifies the contract id and template:

{! URLFOR('/apex/echosign_dev1__AgreementTemplateProcess', null, [masterId=Contract.Id,
templateId='a091x000006eGNdAAM']) } 

... but I would also like to specify an account and contact.