How to track if signed document is already retrieved?

We will be designing a polling mechanism on our end to fetch the status of agreements on a regular basis. If the agreement is ‘SIGNED’ we will go ahead and fetch the document from adobe cloud. However, how can we distinguish if we have already fetched a SIGNED document? If we send Get Agreements Status api, it will provide us the agreement details in response, but how can we know if we have retrieved the document associated with this agreement earlier? Does Adobe API provide any field to check this?