diff --git a/agent/background_review.py b/agent/background_review.py
index d9f6ea5950de..bb879cde1edb 100644
--- a/agent/background_review.py
+++ b/agent/background_review.py
@@ -474,19 +474,21 @@ def _bg_review_auto_deny(command, description, **kwargs):
                     quiet_mode=True,
                 )
             }
+            # Allow read-only file tools for cron background review (issue #45877)
+            review_whitelist.update({"read_file", "search_files"})
             set_thread_tool_whitelist(
                 review_whitelist,
                 deny_msg_fmt=(
                     "Background review denied non-whitelisted tool: "
-                    "{tool_name}. Only memory/skill tools are allowed."
+                    "{tool_name}. Only memory/skill/read-only-file tools are allowed."
                 ),
             )
             try:
                 review_agent.run_conversation(
                     user_message=(
                         prompt
-                        + "\n\nYou can only call memory and skill "
-                        "management tools. Other tools will be denied "
+                        + "\n\nYou can only call memory, skill management, and read-only file "
+                        "tools (read_file, search_files). Other tools will be denied "
                         "at runtime — do not attempt them."
                     ),
                     conversation_history=messages_snapshot,
diff --git a/tests/run_agent/test_background_review_toolset_restriction.py b/tests/run_agent/test_background_review_toolset_restriction.py
index f94ef831ae94..1b79cd5e0e72 100644
--- a/tests/run_agent/test_background_review_toolset_restriction.py
+++ b/tests/run_agent/test_background_review_toolset_restriction.py
@@ -127,12 +127,18 @@ def _no_init(self, *args, **kwargs):
     assert "skill_manage" in whitelist
     assert "skill_view" in whitelist
     assert "skills_list" in whitelist
+    # read-only file tools must be allowed (issue #45877)
+    assert "read_file" in whitelist
+    assert "search_files" in whitelist
     # dangerous tools must NOT be in the whitelist
     assert "terminal" not in whitelist
     assert "send_message" not in whitelist
     assert "delegate_task" not in whitelist
     assert "web_search" not in whitelist
     assert "execute_code" not in whitelist
+    # write file tools must NOT be in the whitelist
+    assert "write_file" not in whitelist
+    assert "patch" not in whitelist
 
 
 def test_background_review_agent_tools_are_limited():