diff --git a/stardog_cloud_mcp/server.py b/stardog_cloud_mcp/server.py
index b49bdb7..5e83c10 100644
--- a/stardog_cloud_mcp/server.py
+++ b/stardog_cloud_mcp/server.py
@@ -140,10 +140,16 @@ async def voicebox_settings() -> str:
         annotations={"title": "Voicebox: Ask Questions", "readOnlyHint": True},
     )
     @tool_logging("voicebox_ask")
+   # async def voicebox_ask(
+   #     question: str,
+    #    conversation_id: Optional[str] = None,
+    #) -> str:
+
     async def voicebox_ask(
         question: str,
-        conversation_id: Optional[str] = None,
+        conversation_id: str = "",
     ) -> str:
+        conversation_id = conversation_id.strip() or None
         """
         Ask a question to Voicebox and get a natural language response
         """
@@ -175,10 +181,16 @@ async def voicebox_ask(
         annotations={"title": "Voicebox: Generate SPARQL", "readOnlyHint": True},
     )
     @tool_logging("voicebox_generate_query")
-    async def voicebox_generate_query(
+   # async def voicebox_generate_query(
+   #     question: str,
+   #     conversation_id: Optional[str] = None,
+   # ) -> str:
+
+        async def voicebox_generate_query(
         question: str,
-        conversation_id: Optional[str] = None,
+        conversation_id: str = "",
     ) -> str:
+        conversation_id = conversation_id.strip() or None
         """
         Generate a SPARQL query from a natural language question using Voicebox
         """