Revisiting the API definition

Let's review Librarian's API definition:

openapi: 3.0.0 
servers: 
  - url: /api 
info: 
  title: Goophr Librarian API 
  version: '1.0' 
  description: | 
    API responsible for indexing & communicating with Goophr Concierge. 
paths: 
  /index: 
    post: 
      description: | 
        Add terms to index. 
      responses: 
        '200': 
          description: | 
            Terms were successfully added to the index. 
        '400': 
          description: > 
            Request was not processed because payload was incomplete or 
            incorrect. 
          content: 
            application/json: 
              schema: 
                $ref: '#/components/schemas/error' 
      requestBody: 
        content: 
          application/json: 
            schema: 
              $ref: &apos...