style: fix lint error

Author: pengqun

src/modelscope_mcp_server/tools/aigc.py

@@ -42,7 +42,8 @@ async def generate_image(
             str | None,
             Field(
                 description="The model's ID to be used for image generation. "
-                "If not provided, the default model for the corresponding generation type (text-to-image or image-to-image) is used."
+                "If not provided, the default model for the corresponding generation type "
+                "(text-to-image or image-to-image) is used."
             ),
         ] = None,
         image_url: Annotated[