feat: Add output schema support to MCP tools

Author: bigdevlarry

src/Server/Builder.php

@@ -88,7 +88,7 @@ final class Builder
      *     annotations: ?ToolAnnotations,
      *     icons: ?Icon[],
      *     meta: ?array<string, mixed>,
-     *     output: ?array<string, mixed>,
+     *     outputSchema: ?array<string, mixed>,
      * }[]
      */
     private array $tools = [];