diff --git a/check_home_assistant_state.py b/check_home_assistant_state.py
index 605060d..96ca580 100755
--- a/check_home_assistant_state.py
+++ b/check_home_assistant_state.py
@@ -138,7 +138,11 @@ class Icinga2ConfAction(argparse.Action):
 def main():
     argp = argparse.ArgumentParser(description=__doc__)
     argp.add_argument(
-        "-t", "--token", required=True, type=str, help="API token for Home Assistant"
+        "-t",
+        "--token",
+        required=True,
+        type=str,
+        help="token for Home Assistant REST API (see https://developers.home-assistant.io/docs/api/rest/)",
     )
     argp.add_argument(
         "-u", "--url", required=True, type=str, help="URL for Home Assistant"