GraphQL连接上的'fields'参数做什么？

我在amplify/graphQL中找不到关于此的任何文档以及它的用途：

为什么会这样：

@connection(keyName: "bySeason", fields: ["id"])`

有什么不同于

@connection(keyName: "bySeason")

示例模型

type League @model
{
  id: ID!
  name: String!
  seasons: [Season] @connection(keyName: "bySeason", fields: ["id"])
}