diff --git a/agent/conversation_loop.py b/agent/conversation_loop.py
index ef69ac68329..163a508a8cd 100644
--- a/agent/conversation_loop.py
+++ b/agent/conversation_loop.py
@@ -3197,15 +3197,22 @@ def run_conversation(
                     # Terminal — flush buffered context so the user sees
                     # what was tried before the abort.
                     agent._flush_status_buffer()
+                    # Summarize once: Cloudflare/proxy HTML challenge pages and
+                    # other raw provider bodies must be collapsed to a short
+                    # one-liner here, otherwise the full page leaks into the
+                    # returned ``error`` field and downstream consumers deliver
+                    # it verbatim (e.g. a cron failure notification dumped a
+                    # ~60KB Cloudflare challenge page as 31 Discord messages).
+                    _nonretryable_summary = agent._summarize_api_error(api_error)
                     if classified.reason == FailoverReason.content_policy_blocked:
                         agent._emit_status(
                             f"❌ Provider safety filter blocked this request: "
-                            f"{agent._summarize_api_error(api_error)}"
+                            f"{_nonretryable_summary}"
                         )
                     else:
                         agent._emit_status(
                             f"❌ Non-retryable error (HTTP {status_code}): "
-                            f"{agent._summarize_api_error(api_error)}"
+                            f"{_nonretryable_summary}"
                         )
                     agent._vprint(f"{agent.log_prefix}❌ Non-retryable client error (HTTP {status_code}). Aborting.", force=True)
                     agent._vprint(f"{agent.log_prefix}   🔌 Provider: {_provider}  Model: {_model}", force=True)
@@ -3309,7 +3316,7 @@ def run_conversation(
                         "api_calls": api_call_count,
                         "completed": False,
                         "failed": True,
-                        "error": str(api_error),
+                        "error": _nonretryable_summary,
                     }
 
                 if retry_count >= max_retries: