diff --git a/custom_components/llama_conversation/__init__.py b/custom_components/llama_conversation/__init__.py
index c033a8d..596c530 100644
--- a/custom_components/llama_conversation/__init__.py
+++ b/custom_components/llama_conversation/__init__.py
@@ -145,7 +145,11 @@ class HassServiceTool(llm.Tool):
         self, hass: HomeAssistant, tool_input: llm.ToolInput, llm_context: llm.LLMContext
     ) -> JsonObjectType:
         """Call the tool."""
-        domain, service = tuple(tool_input.tool_args["service"].split("."))
+        try:
+            domain, service = tuple(tool_input.tool_args["service"].split("."))
+        except ValueError:
+            return { "result": "unknown service" }
+        
         target_device = tool_input.tool_args["target_device"]
 
         if domain not in self.ALLOWED_DOMAINS or service not in self.ALLOWED_SERVICES:
diff --git a/custom_components/llama_conversation/agent.py b/custom_components/llama_conversation/agent.py
index 3d80235..935c42c 100644
--- a/custom_components/llama_conversation/agent.py
+++ b/custom_components/llama_conversation/agent.py
@@ -404,6 +404,7 @@ class LocalLLMAgent(AbstractConversationAgent):
                     tool_args=parsed_tool_call["arguments"],
                 )
 
+            tool_response = None
             try:
                 tool_response = await llm_api.async_call_tool(tool_input)
                 _LOGGER.debug("Tool response: %s", tool_response)