Note: I've created it as a bug, but it can easily be a story (not sure what the requirements were for that fields)

Description:
It's not possible to get the Content Type description using GraphQL.

Example query that I'd like to execute:

{
  _repository
  {
    contentType(id: 1)
    {
      name
      isContainer
      defaultAlwaysAvailable
      # there is no "description" field
    }
  }
}