diff --git a/eval_protocol/mcp/execution/base_policy.py b/eval_protocol/mcp/execution/base_policy.py
index 22bad57e..819b33dd 100644
--- a/eval_protocol/mcp/execution/base_policy.py
+++ b/eval_protocol/mcp/execution/base_policy.py
@@ -182,7 +182,7 @@ async def _generate_live_tool_calls(
         # This is crucial for proper tool call ID management in add_tool_response
         assistant_message_for_history = {
             "role": "assistant",
-            "content": response["choices"][0]["message"]["content"],
+            "content": response["choices"][0]["message"].get("content", ""),
         }
         usage_stats = CompletionUsage(
             prompt_tokens=response["usage"]["prompt_tokens"],