docs: document tool list changed notifications

docs/client.md

@@ -27,6 +27,18 @@ A typical flow:
 
 See [`simpleStreamableHttp.ts`](../examples/client/src/simpleStreamableHttp.ts) for an interactive CLI client that exercises these methods and shows how to handle notifications, elicitation and tasks.
 
+## Notifications
+
+Clients can subscribe to server notifications and react to changes. For example, when the server reports that its tool list changed, refresh your cached tool list:
+
+```typescript
+import { ToolListChangedNotificationSchema } from '@modelcontextprotocol/client';
+
+client.setNotificationHandler(ToolListChangedNotificationSchema, async () => {
+    await client.listTools();
+});
+```
+
 ## Transports and backwards compatibility
 
 To support both modern Streamable HTTP and legacy SSE servers, use a client that:

docs/server.md

@@ -99,6 +99,13 @@ const app = createMcpExpressApp({
 
 Tools let MCP clients ask your server to take actions. They are usually the main way that LLMs call into your application.
 
+When your tool list changes at runtime, the server can notify connected clients so they can refresh their cached tool list. `McpServer` automatically emits a tool list changed notification when you register a new tool. You can also send it manually if you update metadata or
+remove tools:
+
+```typescript
+server.sendToolListChanged();
+```
+
 A typical registration with `registerTool` looks like this:
 
 ```typescript