diff --git a/run_agent.py b/run_agent.py
index da491dde1..bca5571f6 100644
--- a/run_agent.py
+++ b/run_agent.py
@@ -3067,7 +3067,7 @@ class AIAgent:
                         print(f"{self.log_prefix}   📝 Provider message: {error_msg[:200]}")
                         print(f"{self.log_prefix}   ⏱️  Response time: {api_duration:.2f}s (fast response often indicates rate limiting)")
                         
-                        if retry_count > max_retries:
+                        if retry_count >= max_retries:
                             print(f"{self.log_prefix}❌ Max retries ({max_retries}) exceeded for invalid responses. Giving up.")
                             logging.error(f"{self.log_prefix}Invalid API response after {max_retries} retries.")
                             self._persist_session(messages, conversation_history)
@@ -3339,7 +3339,7 @@ class AIAgent:
                                 "partial": True
                             }
                     
-                    if retry_count > max_retries:
+                    if retry_count >= max_retries:
                         print(f"{self.log_prefix}❌ Max retries ({max_retries}) exceeded. Giving up.")
                         logging.error(f"{self.log_prefix}API call failed after {max_retries} retries. Last error: {api_error}")
                         logging.error(f"{self.log_prefix}Request details - Messages: {len(api_messages)}, Approx tokens: {approx_tokens:,}")
diff --git a/tests/test_run_agent.py b/tests/test_run_agent.py
index 2d3703933..92ab23cba 100644
--- a/tests/test_run_agent.py
+++ b/tests/test_run_agent.py
@@ -758,3 +758,49 @@ class TestRunConversation:
             )
             result = agent.run_conversation("search something")
         mock_compress.assert_called_once()
+
+
+class TestRetryExhaustion:
+    """Regression: retry_count > max_retries was dead code (off-by-one).
+
+    When retries were exhausted the condition never triggered, causing
+    the loop to exit and fall through to response.choices[0] on an
+    invalid response, raising IndexError.
+    """
+
+    def _setup_agent(self, agent):
+        agent._cached_system_prompt = "You are helpful."
+        agent._use_prompt_caching = False
+        agent.tool_delay = 0
+        agent.compression_enabled = False
+        agent.save_trajectories = False
+
+    def test_invalid_response_returns_error_not_crash(self, agent):
+        """Exhausted retries on invalid (empty choices) response must not IndexError."""
+        self._setup_agent(agent)
+        # Return response with empty choices every time
+        bad_resp = SimpleNamespace(
+            choices=[],
+            model="test/model",
+            usage=None,
+        )
+        agent.client.chat.completions.create.return_value = bad_resp
+        with (
+            patch.object(agent, "_persist_session"),
+            patch.object(agent, "_save_trajectory"),
+            patch.object(agent, "_cleanup_task_resources"),
+        ):
+            result = agent.run_conversation("hello")
+        assert result.get("failed") is True or result.get("completed") is False
+
+    def test_api_error_raises_after_retries(self, agent):
+        """Exhausted retries on API errors must raise, not fall through."""
+        self._setup_agent(agent)
+        agent.client.chat.completions.create.side_effect = RuntimeError("rate limited")
+        with (
+            patch.object(agent, "_persist_session"),
+            patch.object(agent, "_save_trajectory"),
+            patch.object(agent, "_cleanup_task_resources"),
+        ):
+            with pytest.raises(RuntimeError, match="rate limited"):
+                agent.run_conversation("hello")