diff --git a/tests/tools/test_search_files_engine_selection.py b/tests/tools/test_search_files_engine_selection.py
index 6cdb5e3616..7bda6892b6 100644
--- a/tests/tools/test_search_files_engine_selection.py
+++ b/tests/tools/test_search_files_engine_selection.py
@@ -305,7 +305,9 @@ def test_handler_normalizes_blank_path_to_current_directory(monkeypatch, target,
     assert captured["path"] == "."
 
 
-def test_handler_preserves_nonblank_path(monkeypatch):
+@pytest.mark.parametrize("raw_path", ["src", 5, ["src"]])
+def test_handler_preserves_nonblank_path(monkeypatch, raw_path):
+    """Only None/blank normalise to '.'; a wrong-typed path reaches search_tool's own error path."""
     captured = {}
 
     def fake_search_tool(**kwargs):
@@ -314,9 +316,9 @@ def test_handler_preserves_nonblank_path(monkeypatch):
 
     monkeypatch.setattr("tools.file_tools.search_tool", fake_search_tool)
 
-    registry.dispatch("search_files", {"pattern": "needle", "path": "src"})
+    registry.dispatch("search_files", {"pattern": "needle", "path": raw_path})
 
-    assert captured["path"] == "src"
+    assert captured["path"] == raw_path
 
 
 def test_repeated_search_key_distinguishes_order(monkeypatch):
diff --git a/tools/file_tools.py b/tools/file_tools.py
index 4b312b63e7..a9f264978c 100644
--- a/tools/file_tools.py
+++ b/tools/file_tools.py
@@ -1294,7 +1294,7 @@ def _handle_search_files(args, **kw):
     # The schema documents path='.'; a present-but-blank (or JSON null) value
     # is not a missing key for dict.get, so apply the default here (#112424).
     path = args.get("path", ".")
-    if not isinstance(path, str) or not path.strip():
+    if path is None or (isinstance(path, str) and not path.strip()):
         path = "."
     return search_tool(
         pattern=args.get("pattern", ""), target=target, path=path,