chore(langchain-sdk): Fix type checks (#70)

Author: twishabansal

src/toolbox_langchain_sdk/client.py

@@ -1,5 +1,5 @@
 import asyncio
-from typing import Optional
+from typing import Optional, Type
 
 from aiohttp import ClientSession
 from langchain_core.tools import StructuredTool
@@ -92,7 +92,7 @@ def _generate_tool(
             The generated tool.
         """
         tool_schema = manifest.tools[tool_name]
-        tool_model: BaseModel = _schema_to_model(
+        tool_model: Type[BaseModel] = _schema_to_model(
             model_name=tool_name, schema=tool_schema.parameters
         )