diff --git a/specification/recommendationsservice/resource-manager/Microsoft.RecommendationsService/preview/2021-02-01-preview/recommendationsservice.json b/specification/recommendationsservice/resource-manager/Microsoft.RecommendationsService/preview/2021-02-01-preview/recommendationsservice.json
index 06350a2a5b05..7e2d2637244c 100644
--- a/specification/recommendationsservice/resource-manager/Microsoft.RecommendationsService/preview/2021-02-01-preview/recommendationsservice.json
+++ b/specification/recommendationsservice/resource-manager/Microsoft.RecommendationsService/preview/2021-02-01-preview/recommendationsservice.json
@@ -929,11 +929,6 @@
     "EndpointAuthentication": {
       "description": "Service endpoints authentication details.",
       "type": "object",
-      "required": [
-        "aadTenantID",
-        "principalID",
-        "principalType"
-      ],
       "properties": {
         "aadTenantID": {
           "description": "AAD tenant ID.",
@@ -1023,16 +1018,10 @@
           "$ref": "../../../../../common-types/resource-management/v2/types.json#/definitions/TrackedResource"
         }
       ],
-      "required": [
-        "properties"
-      ],
       "properties": {
         "properties": {
           "description": "Account resource properties.",
           "type": "object",
-          "required": [
-            "configuration"
-          ],
           "properties": {
             "configuration": {
               "description": "Account configuration. This can only be set at RecommendationsService Account creation.",
@@ -1043,7 +1032,6 @@
               ],
               "enum": [
                 "Free",
-                "Explore",
                 "Capacity"
               ],
               "x-ms-enum": {
@@ -1116,9 +1104,6 @@
     "ModelingInputData": {
       "description": "The configuration to raw CDM data to be used as Modeling resource input.",
       "type": "object",
-      "required": [
-        "connectionString"
-      ],
       "properties": {
         "connectionString": {
           "description": "Connection string to raw input data.",
@@ -1134,19 +1119,10 @@
           "$ref": "../../../../../common-types/resource-management/v2/types.json#/definitions/TrackedResource"
         }
       ],
-      "required": [
-        "properties"
-      ],
       "properties": {
         "properties": {
           "description": "Modeling resource properties.",
           "type": "object",
-          "required": [
-            "features",
-            "frequency",
-            "size",
-            "inputData"
-          ],
           "properties": {
             "features": {
               "description": "Modeling features controls the set of supported scenarios\\models being computed. This can only be set at Modeling creation.",
@@ -1162,7 +1138,7 @@
               ],
               "x-ms-enum": {
                 "name": "ModelingFeatures",
-                "modelAsString": false
+                "modelAsString": true
               }
             },
             "frequency": {
@@ -1179,7 +1155,7 @@
               ],
               "x-ms-enum": {
                 "name": "ModelingFrequency",
-                "modelAsString": false
+                "modelAsString": true
               }
             },
             "size": {
@@ -1196,7 +1172,7 @@
               ],
               "x-ms-enum": {
                 "name": "ModelingSize",
-                "modelAsString": false
+                "modelAsString": true
               }
             },
             "inputData": {
@@ -1261,16 +1237,10 @@
           "$ref": "../../../../../common-types/resource-management/v2/types.json#/definitions/TrackedResource"
         }
       ],
-      "required": [
-        "properties"
-      ],
       "properties": {
         "properties": {
           "description": "ServiceEndpoint resource properties.",
           "type": "object",
-          "required": [
-            "preAllocatedCapacity"
-          ],
           "properties": {
             "preAllocatedCapacity": {
               "description": "ServiceEndpoint pre-allocated capacity controls the maximum requests-per-second allowed for that endpoint. Only applicable when Account configuration is Capacity.",