diff --git a/src/JsonRpc/Request.php b/src/JsonRpc/Request.php
index 7b008f0..03298f9 100644
--- a/src/JsonRpc/Request.php
+++ b/src/JsonRpc/Request.php
@@ -42,6 +42,9 @@ public static function fromArray(array $data): static
             throw new \InvalidArgumentException('Invalid or missing "method" for Request.');
         }
         $params = $data['params'] ?? null;
+        if ($params instanceof \stdClass) {
+            $params = (array) $params;
+        }
         if ($params !== null && !is_array($params)) {
             throw new \InvalidArgumentException('"params" for Request must be an array/object or null.');
         }
diff --git a/src/Request/CallToolRequest.php b/src/Request/CallToolRequest.php
index 487302d..c57c713 100644
--- a/src/Request/CallToolRequest.php
+++ b/src/Request/CallToolRequest.php
@@ -52,17 +52,27 @@ public static function fromRequest(Request $request): static
             throw new \InvalidArgumentException('Request is not a call tool request');
         }
 
-        $params = $request->params;
+        $params = $request->params ?? [];
 
-        if (! isset($params['name']) || ! is_string($params['name'])) {
+        if (!isset($params['name']) || !is_string($params['name'])) {
             throw new \InvalidArgumentException("Missing or invalid 'name' parameter for tools/call.");
         }
 
-        $arguments = $params['arguments'] ?? new \stdClass();
-        if (! is_array($arguments) && ! $arguments instanceof \stdClass) {
-            throw new \InvalidArgumentException("Parameter 'arguments' must be an object/array for tools/call.");
+        $arguments = $params['arguments'] ?? [];
+
+        if ($arguments instanceof \stdClass) {
+            $arguments = (array) $arguments;
+        }
+
+        if (!is_array($arguments)) {
+            throw new \InvalidArgumentException("Parameter 'arguments' must be an array.");
         }
 
-        return new static($request->id, $params['name'], $arguments, $params['_meta'] ?? null);
+        return new static(
+            $request->id,
+            $params['name'],
+            $arguments,
+            $params['_meta'] ?? null
+        );
     }
 }