diff --git a/fishctl/src/command/mod.rs b/fishctl/src/command/mod.rs
index b1dc3dd..1c62dd5 100644
--- a/fishctl/src/command/mod.rs
+++ b/fishctl/src/command/mod.rs
@@ -21,8 +21,10 @@ struct Args {
     #[command(subcommand)]
     command: Commands,
 
-    /// parent of the config directory (default: current directory)
-    #[arg(short, long, global = true)]
+    /// Specify the parent of the config directory,
+    /// which typically is Firefish local repo directory
+    /// (default: current directory)
+    #[arg(short = 'd', long, value_name = "PARENT_OF_CONFIG_DIR", global = true)]
     firefish_dir: Option<String>,
 }