diff --git a/sdk/evaluation/azure-ai-evaluation/azure/ai/evaluation/_common/utils.py b/sdk/evaluation/azure-ai-evaluation/azure/ai/evaluation/_common/utils.py
index d02b82741daf..e5a37782036a 100644
--- a/sdk/evaluation/azure-ai-evaluation/azure/ai/evaluation/_common/utils.py
+++ b/sdk/evaluation/azure-ai-evaluation/azure/ai/evaluation/_common/utils.py
@@ -710,6 +710,15 @@ def reformat_conversation_history(query, logger=None, include_system_messages=Fa
         return query
 
 
+def _format_value(v):
+    if isinstance(v, str):
+        return f'"{v}"'
+    elif v is None:
+        return "None"
+    else:
+        return str(v)
+
+
 def _get_agent_response(agent_response_msgs, include_tool_messages=False):
     """Extracts formatted agent response including text, and optionally tool calls/results."""
     agent_response_text = []
@@ -743,7 +752,7 @@ def _get_agent_response(agent_response_msgs, include_tool_messages=False):
                             tool_call_id = content.get("tool_call_id")
                             func_name = content.get("name", "")
                             args = content.get("arguments", {})
-                        args_str = ", ".join(f'{k}="{v}"' for k, v in args.items())
+                        args_str = ", ".join(f"{k}={_format_value(v)}" for k, v in args.items())
                         call_line = f"[TOOL_CALL] {func_name}({args_str})"
                         agent_response_text.append(call_line)
                         if tool_call_id in tool_results: