diff --git a/README.md b/README.md
index ff340919..65b7aaba 100644
--- a/README.md
+++ b/README.md
@@ -32,7 +32,7 @@ usage: optuna-dashboard [-h] [--port PORT] [--host HOST] [--version] [--quiet] s
 Real-time dashboard for Optuna.
 
 positional arguments:
-  storage        Optuna Storage URL
+  storage        DB URL (e.g. sqlite:///example.db)
 
 optional arguments:
   -h, --help     show this help message and exit
diff --git a/optuna_dashboard/cli.py b/optuna_dashboard/cli.py
index 343c19bc..9093f351 100644
--- a/optuna_dashboard/cli.py
+++ b/optuna_dashboard/cli.py
@@ -7,7 +7,7 @@ from .version import __version__
 
 def main():
     parser = argparse.ArgumentParser(description="Real-time dashboard for Optuna.")
-    parser.add_argument("storage", help="Optuna Storage URL", type=str)
+    parser.add_argument("storage", help="DB URL (e.g. sqlite:///example.db)", type=str)
     parser.add_argument(
         "--port", help="port number (default: %(default)s)", type=int, default=8080
     )
diff --git a/setup.py b/setup.py
index 2a42cc93..34f0692e 100644
--- a/setup.py
+++ b/setup.py
@@ -7,7 +7,7 @@ from importlib.machinery import SourceFileLoader
 BASE_PATH = os.path.dirname(__file__)
 
 
-def get_long_description() -> str:
+def get_long_description():
     readme_filepath = os.path.join(BASE_PATH, "README.md")
     with open(readme_filepath) as f:
         return f.read()