diff --git a/strix/llm/llm.py b/strix/llm/llm.py
index 4f624956..57790e40 100644
--- a/strix/llm/llm.py
+++ b/strix/llm/llm.py
@@ -159,12 +159,28 @@ class LLM:
         messages = self._prepare_messages(conversation_history)
         max_retries = int(Config.get("strix_llm_max_retries") or "5")
 
+        bad_request_retried = False
+        bad_request_truncated = False
+
         for attempt in range(max_retries + 1):
             try:
                 async for response in self._stream(messages):
                     yield response
                 return  # noqa: TRY300
             except Exception as e:  # noqa: BLE001
+                if self._is_bad_request(e):
+                    if not bad_request_retried:
+                        bad_request_retried = True
+                        await asyncio.sleep(2)
+                        continue
+                    truncate_enabled = Config.get("strix_truncate_on_oversize") or ""
+                    if (
+                        not bad_request_truncated
+                        and truncate_enabled.lower() in ("1", "true", "yes")
+                        and self._truncate_large_tool_results(messages)
+                    ):
+                        bad_request_truncated = True
+                        continue
                 if attempt >= max_retries or not self._should_retry(e):
                     self._raise_error(e)
                 wait = min(90, 2 * (2**attempt))
@@ -314,6 +330,53 @@ class LLM:
         except Exception:  # noqa: BLE001
             return 0.0
 
+    @staticmethod
+    def _truncate_large_tool_results(
+        messages: list[dict[str, Any]], max_chars: int = 2000
+    ) -> bool:
+        """Aggressively truncate large tool results in messages to recover from BadRequestError.
+
+        Scans messages in reverse for tool_result XML blocks that exceed max_chars and
+        replaces their content with a truncated version plus a skip notice. Returns True
+        if any truncation was performed (caller should retry the request).
+        """
+        import re
+
+        truncated_any = False
+        pattern = re.compile(
+            r"(<tool_result>\s*<tool_name>[^<]*</tool_name>\s*<result>)(.*?)(</result>\s*</tool_result>)",
+            re.DOTALL,
+        )
+
+        for msg in reversed(messages):
+            content = msg.get("content")
+            if not isinstance(content, str) or "<tool_result>" not in content:
+                continue
+
+            def _truncate_match(m: re.Match) -> str:
+                prefix, body, suffix = m.group(1), m.group(2), m.group(3)
+                if len(body) <= max_chars:
+                    return m.group(0)
+                nonlocal truncated_any
+                truncated_any = True
+                kept = body[:1000]
+                return (
+                    f"{prefix}{kept}\n\n... [content truncated from {len(body)} to {len(kept)} chars "
+                    f"due to request size limit — file requires manual review] ...{suffix}"
+                )
+
+            msg["content"] = pattern.sub(_truncate_match, content)
+            if truncated_any:
+                break
+
+        return truncated_any
+
+    def _is_bad_request(self, e: Exception) -> bool:
+        code = getattr(e, "status_code", None) or getattr(
+            getattr(e, "response", None), "status_code", None
+        )
+        return code == 400
+
     def _should_retry(self, e: Exception) -> bool:
         code = getattr(e, "status_code", None) or getattr(
             getattr(e, "response", None), "status_code", None