[Server] Keep injectable parameters out of the published inputSchema (#482)

tests/Integration/Fixture/sampling.php

@@ -16,6 +16,7 @@
 use Mcp\Exception\ClientException;
 use Mcp\Schema\Content\TextContent;
 use Mcp\Server;
+use Mcp\Server\ClientGateway;
 use Mcp\Server\RequestContext;
 use Mcp\Server\Transport\StdioTransport;
 
@@ -38,5 +39,20 @@ Server::builder()
         name: 'summarize',
         description: 'Summarizes text by asking the client to sample.',
     )
+    ->addTool(
+        static function (ClientGateway $client, string $text): string {
+            try {
+                $result = $client->sample($text, maxTokens: 64);
+            } catch (ClientException $e) {
+                return $e->getMessage();
+            }
+
+            assert($result->content instanceof TextContent);
+
+            return sprintf('%s said: %s', $result->model, $result->content->text);
+        },
+        name: 'summarize_via_gateway',
+        description: 'Summarizes text through a directly injected gateway.',
+    )
     ->build()
     ->run(new StdioTransport());