[Automated][azure-resource-manager][skip chg] Update ARM docs for new validation rules

eng/scripts/doc-updater/knowledge/azure-resource-manager.md

@@ -155,3 +155,24 @@ The former multi-purpose `arm-resource-operation` checks are represented by thre
 ## Resource Identity Resolution
 
 Concrete ARM resource identities are seeded only by registered read or createOrUpdate operations with valid ARM resource instance paths. List, action, update, delete, and check-existence operations can attach to an existing resolved resource but do not create resource identities by themselves.
+
+## ARM Operation Query and Payload Rules
+
+- Collection GET operations may use only `api-version` and case-sensitive `$filter` query parameters. Do not recommend `ArmTopParameter`, `ArmSkipParameter`, `order-by`, continuation tokens, or other custom query parameters for collection GET examples.
+- Point GET, PUT, PATCH, and DELETE operations may use only `api-version`.
+- POST operations may use only `api-version`; put request-specific input in a plain request-body model.
+- ARM request bodies must be plain models without indexers. Primitive, union, array, and record request bodies are rejected; bodyless and multipart operations are allowed.
+- ARM request and response bodies must resolve to `application/json`. In particular, `ArmResponse<string>` resolves to a non-JSON scalar response; wrap scalar values in a response model.
+- Collection GET responses should use standard ARM list templates. Custom list operations need `@list`, `@pageItems`, `@nextLink`, and an envelope containing only `value` and `nextLink`.
+
+## Long-Running Operation Results
+
+LRO final-result metadata must match operation semantics: PUT and PATCH return the resource, DELETE returns `void`, and POST actions use their response type (or `void` for no-content actions). Standard async templates configure these defaults. When overriding `LroHeaders`, preserve the matching `FinalResult`.
+
+## Feature File Versions
+
+`ArmFeatureFileOptions.version` optionally selects the API version used for clients generated from that feature file. Empty or whitespace-only values are invalid. This property exists only on the current `Azure.ResourceManager.featureFileOptions`; do not document it on deprecated `Legacy.featureOptions`. Feature files remain restricted to approved brownfield migrations.
+
+## Documentation Sample Links
+
+When linking to a canonical sample from an ARM guide, prefer its published documentation URL under `https://azure.github.io/typespec-azure/docs/samples/resource-manager/` instead of the GitHub source-tree URL.

eng/scripts/doc-updater/knowledge/azure-resource-manager.meta.json

@@ -1,6 +1,6 @@
 {
-  "lastCommit": "ec0efa31cccaadaf340043532eeaa62590ec9272",
-  "lastUpdated": "2026-08-31T09:31:31.540Z",
+  "lastCommit": "b85682f40152971d00d8bdcb4f6204d9c794bf3b",
+  "lastUpdated": "2026-09-21T09:25:43.311Z",
   "analyzedPaths": [
     "packages/typespec-azure-resource-manager/src",
     "packages/typespec-azure-resource-manager/lib",

website/src/content/docs/docs/getstarted/azure-resource-manager/step04.md

@@ -18,6 +18,12 @@ model NotificationDetails {
   urgent: boolean;
 }
 
+/** The result of sending a notification */
+model NotificationResult {
+  /** The identifier for the sent notification */
+  notificationId: string;
+}
+
 @armResourceOperations
 interface Users {
   get is ArmResourceRead<User>;
@@ -53,10 +59,11 @@ In a custom operation, you define the operation parameters, responses, http verb
 
 ```typespec
 /** Send a notification to the user */
+@armResourceAction(User)
 @post
 @segment("notify")
 op NotifyUser(...ResourceInstanceParameters<User>, @body notification: NotificationDetails):
-  | ArmResponse<string>
+  | ArmResponse<NotificationResult>
   | ErrorResponse;
 ```