diff --git a/tools/buildman/builder.py b/tools/buildman/builder.py
index 081c1d0..a41d0b3 100644
--- a/tools/buildman/builder.py
+++ b/tools/buildman/builder.py
@@ -337,7 +337,7 @@
 
         show_errors: True to show summarised error/warning info
         show_sizes: Show size deltas
-        show_detail: Show detail for each board
+        show_detail: Show size delta detail for each board if show_sizes
         show_bloat: Show detail for each function
         list_error_boards: Show the boards which caused each error/warning
         show_config: Show config deltas
@@ -1000,7 +1000,7 @@
                 board.target
             board_dict: Dict containing boards for which we built this
                 commit, keyed by board.target. The value is an Outcome object.
-            show_detail: Show detail for each board
+            show_detail: Show size delta detail for each board
             show_bloat: Show detail for each function
         """
         arch_list = {}
@@ -1117,7 +1117,7 @@
             environment: Dictionary keyed by environment variable, Each
                      value is the value of environment variable.
             show_sizes: Show image size deltas
-            show_detail: Show detail for each board
+            show_detail: Show size delta detail for each board if show_sizes
             show_bloat: Show detail for each function
             show_config: Show config changes
             show_environment: Show environment changes
diff --git a/tools/buildman/cmdline.py b/tools/buildman/cmdline.py
index c7b4bf6..74b4100 100644
--- a/tools/buildman/cmdline.py
+++ b/tools/buildman/cmdline.py
@@ -31,7 +31,7 @@
           help='Reconfigure for every commit (disable incremental build)')
     parser.add_option('-d', '--detail', dest='show_detail',
           action='store_true', default=False,
-          help='Show detailed information for each board in summary')
+          help='Show detailed size delta for each board in the -S summary')
     parser.add_option('-D', '--config-only', action='store_true', default=False,
           help="Don't build, just configure each commit")
     parser.add_option('-e', '--show_errors', action='store_true',