- Updated schema descriptions

Author: Prabhu Ram

app/code/Magento/QuoteGraphQl/etc/schema.graphqls

@@ -22,7 +22,7 @@ type Mutation {
     setPaymentMethodAndPlaceOrder(input: SetPaymentMethodAndPlaceOrderInput): PlaceOrderOutput @deprecated(reason: "Should use setPaymentMethodOnCart and placeOrder mutations in single request.") @resolver(class: "\\Magento\\QuoteGraphQl\\Model\\Resolver\\SetPaymentAndPlaceOrder")
     mergeCarts(source_cart_id: String!, destination_cart_id: String!): Cart! @doc(description:"Merges the source cart into the destination cart") @resolver(class: "Magento\\QuoteGraphQl\\Model\\Resolver\\MergeCarts")
     placeOrder(input: PlaceOrderInput): PlaceOrderOutput @resolver(class: "\\Magento\\QuoteGraphQl\\Model\\Resolver\\PlaceOrder")
-    addProductsToCart(cartId: String!, cartItems: [CartItemInput!]!): AddProductsToCartOutput @doc(description:"Add products to the cart. Provide single interface for all product types ") @resolver(class: "Magento\\QuoteGraphQl\\Model\\Resolver\\AddProductsToCart")
+    addProductsToCart(cartId: String!, cartItems: [CartItemInput!]!): AddProductsToCartOutput @doc(description:"Add any type of product to the cart") @resolver(class: "Magento\\QuoteGraphQl\\Model\\Resolver\\AddProductsToCart")
 }
 
 input createEmptyCartInput {
@@ -52,9 +52,9 @@ input VirtualProductCartItemInput {
 input CartItemInput {
     sku: String!
     quantity: Float!
-    parent_sku: String,
-    selected_options: [ID!]
-    entered_options: [EnteredOptionInput!]
+    parent_sku: String @doc(description: "For child products, the SKU of its parent product")
+    selected_options: [ID!] @doc(description: "The selected options for the base product, such as color or size")
+    entered_options: [EnteredOptionInput!] @doc(description: "An array of entered options for the base product, such as personalization text")
 }
 
 input CustomizableOptionInput {
@@ -373,15 +373,15 @@ type Order {
     order_id: String @deprecated(reason: "The order_id field is deprecated, use order_number instead.")
 }
 
-type CheckoutUserInputError @doc(description:"An error encountered while adding an item the the cart.") {
-    message: String! @doc(description: "Localized error message")
+type CheckoutUserInputError @doc(description:"An error encountered while adding an item to the the cart.") {
+    message: String! @doc(description: "A localized error message")
     path: [String]! @doc(description: "Path to the input field that caused an error. See the GraphQL specification about path errors for details: http://spec.graphql.org/draft/#sec-Errors")
     code: CheckoutUserInputErrorCodes! @doc(description: "Checkout-specific error code")
 }
 
 type AddProductsToCartOutput {
-    cart: Cart!
-    userInputErrors:[CheckoutUserInputError]!
+    cart: Cart! @doc(description: "The cart after products have been added")
+    userInputErrors:[CheckoutUserInputError]! @doc(description: "An error encountered while adding an item to the cart.")
 }
 
 enum CheckoutUserInputErrorCodes {