feat(everything): add tool-level annotations to get-annotated-message

Add readOnlyHint, destructiveHint, idempotentHint, and openWorldHint
annotations to the tool config. Update docs to reflect that this tool
now demonstrates both tool-level and content annotations.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/everything/docs/structure.md

@@ -129,7 +129,7 @@ src/everything
 - `echo.ts`
   - Registers an `echo` tool that takes a message and returns `Echo: {message}`.
 - `get-annotated-message.ts`
-  - Registers an `annotated-message` tool which demonstrates annotated content items by emitting a primary `text` message with `annotations` that vary by `messageType` (`"error" | "success" | "debug"`), and optionally includes an annotated `image` (tiny PNG) when `includeImage` is true.
+  - Registers an `annotated-message` tool which demonstrates both tool-level annotations (`readOnlyHint`, `destructiveHint`, `idempotentHint`, `openWorldHint`) and content annotations. Emits a primary `text` message with content `annotations` (`priority`, `audience`) that vary by `messageType` (`"error" | "success" | "debug"`), and optionally includes an annotated `image` (tiny PNG) when `includeImage` is true.
 - `get-env.ts`
   - Registers a `get-env` tool that returns the current process environment variables as formatted JSON text; useful for debugging configuration.
 - `get-resource-links.ts`

src/everything/tools/get-annotated-message.ts

@@ -21,6 +21,12 @@ const config = {
   description:
     "Demonstrates how annotations can be used to provide metadata about content.",
   inputSchema: GetAnnotatedMessageSchema,
+  annotations: {
+    readOnlyHint: true,       // This tool only returns data, no side effects
+    destructiveHint: false,   // Does not delete or modify anything
+    idempotentHint: true,     // Same input always produces same output
+    openWorldHint: false,     // Does not interact with external systems
+  },
 };
 
 /**