Description Field Missing from __schema

I am not aware of a description on schema level on the official Graphql Spec. Descriptions are available on fields and on types if i’m not mistaken.

reference: GraphQL introspection query - for fetching the whole schema (from GraphiQL IDE) for https://atheros.ai/blog/graphql-introspection-and-introspection-queries · GitHub

reference: Designing GraphQL schemas - Dgraph Blog.

As for the error you are getting, __schema hasn’t got a description field as a direct child so it cannot be queried.