diff --git a/services/transfer_service.go b/services/transfer_service.go
index c123c994..e12ca333 100644
--- a/services/transfer_service.go
+++ b/services/transfer_service.go
@@ -61,9 +61,9 @@ type TransferRequest struct {
 	// name of destination database
 	Destination string `json:"destination" example:"kbase" doc:"destination database identifier"`
 	// a Markdown description of the transfer request
-	Description string `json:"description" example:"# title\n* type: assembly\n" doc:"Markdown task description"`
+	Description string `json:"description,omitempty" example:"# title\n* type: assembly\n" doc:"Markdown task description"`
 	// machine-readable instructions for processing a payload at the destination site
-	Instructions json.RawMessage `json:"instructions" doc:"JSON object containing machine-readable instructions for processing payload at destination"`
+	Instructions json.RawMessage `json:"instructions,omitempty" doc:"JSON object containing machine-readable instructions for processing payload at destination"`
 }
 
 // a response for a file transfer request (POST)