[Server] Address review: cover listChanged-only kinds, clarify bus docblock

Author: chr-hertel

src/Server/Builder.php

@@ -313,11 +313,11 @@ public function setServerInfo(
      * runtimes; under PHP-FPM, where they are different workers, use
      * {@see Psr16NotificationBus} or an implementation over your own broker.
      *
-     * Registry changes are published automatically, with or without an event
-     * dispatcher, unless you pass your own registry with setRegistry(), and
-     * only then is `listChanged` announced. Anything
-     * else, `notifications/resources/updated` for example, is published by the
-     * application calling {@see NotificationBusInterface::publish()}.
+     * With the built-in registry, registry changes are published automatically,
+     * with or without an event dispatcher, and `listChanged` is announced. A
+     * registry passed with setRegistry() is neither published nor announced.
+     * Anything else, `notifications/resources/updated` for example, is
+     * published by the application calling {@see NotificationBusInterface::publish()}.
      */
     public function setNotificationBus(NotificationBusInterface $bus): self
     {

tests/Unit/Schema/ServerCapabilitiesTest.php

@@ -429,4 +429,28 @@ public function testWithExtensionsKeepsTasks(): void
 
         $this->assertSame(['list' => []], $capabilities->tasks);
     }
+
+    public function testWithoutListChangedKeepsKindsAnnouncedOnlyThroughListChanged(): void
+    {
+        $capabilities = (new ServerCapabilities(
+            tools: false,
+            toolsListChanged: true,
+            resources: false,
+            resourcesListChanged: true,
+            prompts: false,
+            promptsListChanged: true,
+        ))->withoutListChanged();
+
+        $this->assertTrue($capabilities->tools);
+        $this->assertFalse($capabilities->toolsListChanged);
+        $this->assertTrue($capabilities->resources);
+        $this->assertFalse($capabilities->resourcesListChanged);
+        $this->assertTrue($capabilities->prompts);
+        $this->assertFalse($capabilities->promptsListChanged);
+        $this->assertEquals([
+            'prompts' => new \stdClass(),
+            'resources' => new \stdClass(),
+            'tools' => new \stdClass(),
+        ], $capabilities->jsonSerialize());
+    }
 }