Adopt server examples

src/Schema/Implementation.php

@@ -23,6 +23,7 @@ class Implementation implements \JsonSerializable
     public function __construct(
         public readonly string $name = 'app',
         public readonly string $version = 'dev',
+        public readonly ?string $description = null,
     ) {
     }
 
@@ -41,7 +42,7 @@ class Implementation implements \JsonSerializable
             throw new InvalidArgumentException('Invalid or missing "version" in Implementation data.');
         }
 
-        return new self($data['name'], $data['version']);
+        return new self($data['name'], $data['version'], $data['description'] ?? null);
     }
 
     /**
@@ -52,9 +53,15 @@ class Implementation implements \JsonSerializable
      */
     public function jsonSerialize(): array
     {
-        return [
+        $data = [
             'name' => $this->name,
             'version' => $this->version,
         ];
+
+        if (null !== $this->description) {
+            $data['description'] = $this->description;
+        }
+
+        return $data;
     }
 }

src/Schema/JsonRpc/HasMethodInterface.php

@@ -1,7 +1,5 @@
 <?php
 
-declare(strict_types=1);
-
 /*
  * This file is part of the official PHP MCP SDK.
  *

src/Schema/JsonRpc/MessageInterface.php

@@ -19,4 +19,5 @@ namespace Mcp\Schema\JsonRpc;
 interface MessageInterface extends \JsonSerializable
 {
     public const JSONRPC_VERSION = '2.0';
+    public const PROTOCOL_VERSION = '2025-06-18';
 }

src/Schema/JsonRpc/Notification.php

@@ -27,7 +27,7 @@ abstract class Notification implements HasMethodInterface, MessageInterface
     /**
      * @var array<string, mixed>|null
      */
-    protected ?array $meta;
+    protected ?array $meta = null;
 
     abstract public static function getMethod(): string;
 

src/Schema/JsonRpc/Request.php

@@ -29,7 +29,7 @@ abstract class Request implements HasMethodInterface, MessageInterface
     /**
      * @var array<string, mixed>|null
      */
-    protected ?array $meta;
+    protected ?array $meta = null;
 
     abstract public static function getMethod(): string;
 

src/Schema/Request/CreateSamplingMessageRequest.php

@@ -11,6 +11,7 @@
 
 namespace Mcp\Schema\Request;
 
+use Mcp\Exception\InvalidArgumentException;
 use Mcp\Schema\Content\SamplingMessage;
 use Mcp\Schema\JsonRpc\Request;
 use Mcp\Schema\ModelPreferences;
@@ -61,11 +62,11 @@ class CreateSamplingMessageRequest extends Request
     protected static function fromParams(?array $params): Request
     {
         if (!isset($params['messages']) || !\is_array($params['messages'])) {
-            throw new \InvalidArgumentException('Missing or invalid "messages" parameter for sampling/createMessage.');
+            throw new InvalidArgumentException('Missing or invalid "messages" parameter for sampling/createMessage.');
         }
 
         if (!isset($params['maxTokens']) || !\is_int($params['maxTokens'])) {
-            throw new \InvalidArgumentException('Missing or invalid "maxTokens" parameter for sampling/createMessage.');
+            throw new InvalidArgumentException('Missing or invalid "maxTokens" parameter for sampling/createMessage.');
         }
 
         $preferences = null;

src/Schema/Result/EmptyResult.php

@@ -35,8 +35,8 @@ class EmptyResult implements ResultInterface
     /**
      * @return array{}
      */
-    public function jsonSerialize(): array
+    public function jsonSerialize(): object
     {
-        return [];
+        return new \stdClass();
     }
 }

src/Schema/Result/InitializeResult.php

@@ -82,7 +82,7 @@ class InitializeResult implements ResultInterface
     public function jsonSerialize(): array
     {
         $data = [
-            'protocolVersion' => MessageInterface::JSONRPC_VERSION,
+            'protocolVersion' => MessageInterface::PROTOCOL_VERSION,
             'capabilities' => $this->capabilities,
             'serverInfo' => $this->serverInfo,
         ];

src/Schema/Result/ListPromptsResult.php

@@ -64,7 +64,7 @@ class ListPromptsResult implements ResultInterface
     public function jsonSerialize(): array
     {
         $result = [
-            'prompts' => $this->prompts,
+            'prompts' => array_values($this->prompts),
         ];
 
         if ($this->nextCursor) {

src/Schema/Result/ListResourceTemplatesResult.php

@@ -64,7 +64,7 @@ class ListResourceTemplatesResult implements ResultInterface
     public function jsonSerialize(): array
     {
         $result = [
-            'resourceTemplates' => $this->resourceTemplates,
+            'resourceTemplates' => array_values($this->resourceTemplates),
         ];
 
         if ($this->nextCursor) {

src/Schema/Result/ListResourcesResult.php

@@ -64,7 +64,7 @@ class ListResourcesResult implements ResultInterface
     public function jsonSerialize(): array
     {
         $result = [
-            'resources' => $this->resources,
+            'resources' => array_values($this->resources),
         ];
 
         if (null !== $this->nextCursor) {

src/Schema/Result/ListRootsResult.php

@@ -42,7 +42,7 @@ class ListRootsResult implements ResultInterface
     public function jsonSerialize(): array
     {
         $result = [
-            'roots' => $this->roots,
+            'roots' => array_values($this->roots),
         ];
 
         if (null !== $this->_meta) {

src/Schema/Result/ListToolsResult.php

@@ -64,7 +64,7 @@ class ListToolsResult implements ResultInterface
     public function jsonSerialize(): array
     {
         $result = [
-            'tools' => $this->tools,
+            'tools' => array_values($this->tools),
         ];
 
         if ($this->nextCursor) {

src/Schema/Result/ReadResourceResult.php

@@ -13,8 +13,8 @@ namespace Mcp\Schema\Result;
 
 use Mcp\Exception\InvalidArgumentException;
 use Mcp\Schema\Content\BlobResourceContents;
+use Mcp\Schema\Content\ResourceContents;
 use Mcp\Schema\Content\TextResourceContents;
-use Mcp\Schema\JsonRpc\Response;
 use Mcp\Schema\JsonRpc\ResultInterface;
 
 /**
@@ -30,7 +30,7 @@ class ReadResourceResult implements ResultInterface
     /**
      * Create a new ReadResourceResult.
      *
-     * @param array<TextResourceContents|BlobResourceContents> $contents The contents of the resource
+     * @param ResourceContents[] $contents The contents of the resource
      */
     public function __construct(
         public readonly array $contents,