diff --git a/src/cpu.py b/src/cpu.py
index 63b92d5..8164c11 100644
--- a/src/cpu.py
+++ b/src/cpu.py
@@ -20,7 +20,11 @@ def main(args):
 
 if __name__ == "__main__":
     parser = argparse.ArgumentParser()
-    parser.add_argument("-i", "--interval", type=int, default=1)
-    parser.add_argument("--percpu", action="store_true", default=False)
+    parser.add_argument(
+        "-i", "--interval", type=int, default=1, help="interval in seconds"
+    )
+    parser.add_argument(
+        "--percpu", action="store_true", default=False, help="display per cpu usage"
+    )
     args = parser.parse_args()
     main(args)
diff --git a/src/disk.py b/src/disk.py
index d5d473d..3a19f81 100644
--- a/src/disk.py
+++ b/src/disk.py
@@ -63,8 +63,22 @@ def main(args):
 if __name__ == "__main__":
     parser = argparse.ArgumentParser()
     group = parser.add_mutually_exclusive_group()
-    group.add_argument("-t", "--total", action="store_true", default=False)
-    group.add_argument("-f", "--free", action="store_true", default=False)
-    parser.add_argument("-p", "--path", type=str, default=None)
+    group.add_argument(
+        "-t",
+        "--total",
+        action="store_true",
+        default=False,
+        help="display disk usage as used/total in GB",
+    )
+    group.add_argument(
+        "-f",
+        "--free",
+        action="store_true",
+        default=False,
+        help="display free disk in GB",
+    )
+    parser.add_argument(
+        "-p", "--path", type=str, default=None, help="path to check disk usage"
+    )
     args = parser.parse_args()
     main(args)
diff --git a/src/mem.py b/src/mem.py
index 04cdcd7..6ff3574 100644
--- a/src/mem.py
+++ b/src/mem.py
@@ -29,6 +29,12 @@ def main(args):
 
 if __name__ == "__main__":
     parser = argparse.ArgumentParser()
-    parser.add_argument("-t", "--total", action="store_true", default=False)
+    parser.add_argument(
+        "-t",
+        "--total",
+        action="store_true",
+        default=False,
+        help="display memory usage as used/total in GB",
+    )
     args = parser.parse_args()
     main(args)