diff --git a/run_agent.py b/run_agent.py
index 360ef0517..4c0d3be4b 100644
--- a/run_agent.py
+++ b/run_agent.py
@@ -9736,12 +9736,25 @@ class AIAgent:
                     
                     # Pop thinking-only prefill message(s) before appending
                     # (tool-call path — same rationale as the final-response path).
+                    _had_prefill = False
                     while (
                         messages
                         and isinstance(messages[-1], dict)
                         and messages[-1].get("_thinking_prefill")
                     ):
                         messages.pop()
+                        _had_prefill = True
+
+                    # Reset prefill counter when tool calls follow a prefill
+                    # recovery.  Without this, the counter accumulates across
+                    # the whole conversation — a model that intermittently
+                    # empties (empty → prefill → tools → empty → prefill →
+                    # tools) burns both prefill attempts and the third empty
+                    # gets zero recovery.  Resetting here treats each tool-
+                    # call success as a fresh start.
+                    if _had_prefill:
+                        self._thinking_prefill_retries = 0
+                        self._empty_content_retries = 0
 
                     messages.append(assistant_msg)
                     self._emit_interim_assistant_message(assistant_msg)
@@ -9917,16 +9930,23 @@ class AIAgent:
                             self._save_session_log(messages)
                             continue
 
-                        # ── Empty response retry (no reasoning) ──────
-                        # Model returned nothing — no content, no
-                        # structured reasoning, no tool calls.  Common
-                        # with open models (transient provider issues,
-                        # rate limits, sampling flukes).  Retry up to 3
-                        # times before attempting fallback.  Skip when
-                        # content has inline <think> tags (model chose
-                        # to reason, just no visible text).
-                        _truly_empty = not final_response.strip()
-                        if _truly_empty and not _has_structured and self._empty_content_retries < 3:
+                        # ── Empty response retry ──────────────────────
+                        # Model returned nothing usable.  Retry up to 3
+                        # times before attempting fallback.  This covers
+                        # both truly empty responses (no content, no
+                        # reasoning) AND reasoning-only responses after
+                        # prefill exhaustion — models like mimo-v2-pro
+                        # always populate reasoning fields via OpenRouter,
+                        # so the old `not _has_structured` guard blocked
+                        # retries for every reasoning model after prefill.
+                        _truly_empty = not self._strip_think_blocks(
+                            final_response
+                        ).strip()
+                        _prefill_exhausted = (
+                            _has_structured
+                            and self._thinking_prefill_retries >= 2
+                        )
+                        if _truly_empty and (not _has_structured or _prefill_exhausted) and self._empty_content_retries < 3:
                             self._empty_content_retries += 1
                             logger.warning(
                                 "Empty response (no content or reasoning) — "
diff --git a/tests/run_agent/test_run_agent.py b/tests/run_agent/test_run_agent.py
index e4ae10f20..2112ddc3f 100644
--- a/tests/run_agent/test_run_agent.py
+++ b/tests/run_agent/test_run_agent.py
@@ -1741,9 +1741,9 @@ class TestRunConversation:
             {"role": "assistant", "content": "old answer"},
         ]
 
-        # 3 responses: original + 2 prefill continuations (structured reasoning triggers prefill)
+        # 6 responses: original + 2 prefill + 3 retries after prefill exhaustion
         with (
-            patch.object(agent, "_interruptible_api_call", side_effect=[empty_resp, empty_resp, empty_resp]),
+            patch.object(agent, "_interruptible_api_call", side_effect=[empty_resp] * 6),
             patch.object(agent, "_compress_context") as mock_compress,
             patch.object(agent, "_persist_session"),
             patch.object(agent, "_save_trajectory"),
@@ -1754,18 +1754,18 @@ class TestRunConversation:
         mock_compress.assert_not_called()  # no compression triggered
         assert result["completed"] is True
         assert result["final_response"] == "(empty)"
-        assert result["api_calls"] == 3  # 1 original + 2 prefill continuations
+        assert result["api_calls"] == 6  # 1 original + 2 prefill + 3 retries
 
     def test_reasoning_only_response_prefill_then_empty(self, agent):
-        """Structured reasoning-only triggers prefill continuation (up to 2), then falls through to (empty)."""
+        """Structured reasoning-only triggers prefill (2), then retries (3), then (empty)."""
         self._setup_agent(agent)
         empty_resp = _mock_response(
             content=None,
             finish_reason="stop",
             reasoning_content="structured reasoning answer",
         )
-        # 3 responses: original + 2 prefill continuations, all reasoning-only
-        agent.client.chat.completions.create.side_effect = [empty_resp, empty_resp, empty_resp]
+        # 6 responses: 1 original + 2 prefill + 3 retries after prefill exhaustion
+        agent.client.chat.completions.create.side_effect = [empty_resp] * 6
         with (
             patch.object(agent, "_persist_session"),
             patch.object(agent, "_save_trajectory"),
@@ -1774,7 +1774,7 @@ class TestRunConversation:
             result = agent.run_conversation("answer me")
         assert result["completed"] is True
         assert result["final_response"] == "(empty)"
-        assert result["api_calls"] == 3  # 1 original + 2 prefill continuations
+        assert result["api_calls"] == 6  # 1 original + 2 prefill + 3 retries
 
     def test_reasoning_only_prefill_succeeds_on_continuation(self, agent):
         """When prefill continuation produces content, it becomes the final response."""