diff --git a/tests/test_tool_definition_invariants.py b/tests/test_tool_definition_invariants.py
new file mode 100644
index 0000000000..b1255d2f4c
--- /dev/null
+++ b/tests/test_tool_definition_invariants.py
@@ -0,0 +1,17 @@
+import re
+import pytest
+
+def validate_mcp_tool_name(name: str) -> bool:
+    if not name or not (1 <= len(name) <= 64):
+        return False
+    return bool(re.match(r"^[a-zA-Z0-9_-]+$", name))
+
+def test_valid_mcp_tool_names():
+    assert validate_mcp_tool_name("query_database") is True
+    assert validate_mcp_tool_name("fetch-api-v2") is True
+    assert validate_mcp_tool_name("search123") is True
+
+def test_invalid_mcp_tool_names():
+    assert validate_mcp_tool_name("") is False
+    assert validate_mcp_tool_name("tool with spaces") is False
+    assert validate_mcp_tool_name("tool.with.dots") is False