[DOCS] Edit migration summaries (#3298)

(cherry picked from commit a2e56ab)

Author: lcawl

output/openapi/elasticsearch-openapi.json

@@ -21,8 +21,13 @@ import { RequestBase } from '@_types/Base'
 import { IndexName } from '@_types/common'
 
 /**
+ * Get deprecation information.
+ * Get information about different cluster, node, and index level settings that use deprecated features that will be removed or changed in the next major version.
+ *
+ * TIP: This APIs is designed for indirect use by the Upgrade Assistant. We strongly recommend you use the Upgrade Assistant.
  * @rest_spec_name migration.deprecations
  * @availability stack since=6.1.0 stability=stable
+ * @cluster_privileges manage
  */
 export interface Request extends RequestBase {
   path_parts: {

output/schema/schema.json

@@ -20,8 +20,15 @@
 import { RequestBase } from '@_types/Base'
 
 /**
+ * Get feature migration information.
+ * Version upgrades sometimes require changes to how features store configuration information and data in system indices.
+ * Check which features need to be migrated and the status of any migrations that are in progress.
+ *
+ * TIP: This API is designed for indirect use by the Upgrade Assistant.
+ * We strongly recommend you use the Upgrade Assistant.
  * @rest_spec_name migration.get_feature_upgrade_status
  * @availability stack since=7.16.0 stability=stable
  * @index_privileges manage
+ * @cluster_privileges manage
  */
 export interface Request extends RequestBase {}

specification/migration/deprecations/DeprecationInfoRequest.ts

@@ -20,8 +20,16 @@
 import { RequestBase } from '@_types/Base'
 
 /**
+ * Start the feature migration.
+ * Version upgrades sometimes require changes to how features store configuration information and data in system indices.
+ * This API starts the automatic migration process.
+ *
+ * Some functionality might be temporarily unavailable during the migration process.
+ *
+ * TIP: The API is designed for indirect use by the Upgrade Assistant. We strongly recommend you use the Upgrade Assistant.
  * @rest_spec_name migration.post_feature_upgrade
  * @availability stack since=7.16.0 stability=stable
  * @index_privileges manage
+ * @cluster_privileges manage
  */
 export interface Request extends RequestBase {}