Grape-Swagger: Route Parameter issues

I am using grape-swagger to show documentation on my Ruby API I'm building using Grape.

I am adding descriptions to all of my parameters on my endpoints but I can't seem to find anything about how to add descriptions to route parameters.

I have tried the following:

route_param :monitor_name, type: String, desc: 'The name of the monitor that is being retrieved.' do

and

route_param :monitor_name, type: String, description: 'The name of the monitor that is being retrieved.' do

but neither of those will display the actual description on the swagger UI.

Any ideas?

p.s. (the only thing I found in the grape documentation is shown in the attach image)