1. A method comprising: determining, by a processing device, that a document accessed from a computer-readable medium lacks existing metadata describing a field in the document; performing, by the processing device and based on determining that the document lacks the existing metadata, document-modification operations comprising: determining, by the processing device, that data entered into the field of the document corresponds to a value of a field description included in a user profile, and modifying, by the processing device and based on the data entered into the field corresponding to the value of the field description, the document to include a tag that is applied to the field, wherein the tag comprises metadata with the field description; and performing, by a document management application executed by the processing device and accessed with the user profile, operations comprising: scanning a user document associated with the user profile, identifying, from scanning the user document, a link to a web document at a remote resource, wherein the remote resource is independent of the document management application and accessible by the document management application via a data network, executing a crawler process that accesses, via the link, the web document from the remote resource and that identifies a web field in the web document, generating, from the crawler process, remote document data in a locally accessible storage location in which the document is stored, wherein the remote document data is generated specifically for the web document and associates the field description with the web field, modifying, based on identifying changed data in the field of the document, the remote document data to include the changed data for the field description, and updating the web field at the remote resource by copying the changed data from the remote document data to the web field of the web document at the remote resource, wherein the web field at the remote resource is updated based on the remote document data being modified to include the changed data for the field description.