diff --git a/litellm/router_utils/common_utils.py b/litellm/router_utils/common_utils.py
index 15725e30d04..10acc343abd 100644
--- a/litellm/router_utils/common_utils.py
+++ b/litellm/router_utils/common_utils.py
@@ -110,7 +110,7 @@ def filter_web_search_deployments(
         return healthy_deployments
 
     is_web_search_request = False
-    tools = request_kwargs.get("tools", [])
+    tools = request_kwargs.get("tools") or []
     for tool in tools:
         # These are the two websearch tools for OpenAI / Azure. 
         if tool.get("type") == "web_search" or tool.get("type") == "web_search_preview":
diff --git a/tests/test_litellm/router_utils/test_router_utils_common_utils.py b/tests/test_litellm/router_utils/test_router_utils_common_utils.py
index f73609d47ba..8ff1ba45cc2 100644
--- a/tests/test_litellm/router_utils/test_router_utils_common_utils.py
+++ b/tests/test_litellm/router_utils/test_router_utils_common_utils.py
@@ -248,6 +248,11 @@ class TestFilterWebSearchDeployments:
         result = filter_web_search_deployments(sample_deployments, {"tools": []})
         assert result == sample_deployments
 
+    def test_none_tools_returns_all(self, sample_deployments):
+        """When tools is explicitly None, return all deployments (regression test for #17672)"""
+        result = filter_web_search_deployments(sample_deployments, {"tools": None})
+        assert result == sample_deployments
+
     def test_non_web_search_tools_returns_all(self, sample_deployments):
         """When tools don't include web_search, return all deployments"""
         request_kwargs = {"tools": [{"type": "function", "function": {}}]}