diff --git a/doc/user_guide.md b/doc/user_guide.md
index 20a97fa..3fb5a0c 100644
--- a/doc/user_guide.md
+++ b/doc/user_guide.md
@@ -147,17 +147,49 @@ Rscons is typically invoked from the command-line as `./rscons`.
     Usage: ./rscons [global options] [[task] [task options] ...]
 
     Global options:
-      -A, --all                   Show all tasks (even without descriptions) in task list
-      -b BUILD, --build=BUILD     Set build directory (default: build)
-      -e VS, --variants=VS        Enable or disable variants
-      -f FILE                     Use FILE as Rsconscript
-      -F, --show-failure          Show failed command log from previous build and exit
-      -h, --help                  Show rscons help and exit
-      -j N, --nthreads=N          Set number of threads
-      -r COLOR, --color=COLOR     Set color mode (off, auto, force)
-      -T, --tasks                 Show task list and parameters and exit
-      -v, --verbose               Run verbosely
-      --version                   Show rscons version and exit
+      -A, --all
+        Show all tasks (even those without descriptions) in task list. Use in
+        conjunction with the -T argument.
+
+      -b BUILD, --build=BUILD
+        Set build directory (default: build).
+
+      -e VS, --variants=VS
+        Enable or disable variants. VS is a comma-separated list of variant
+        entries. If the entry begins with "-" the variant is disabled instead of
+        enabled. If the full list begins with "+" or "-" then it modifies the
+        variants that are enabled by default by only enabling or disabling the
+        listed variants. Otherwise, the enabled set of variants is as given and
+        any variants not listed are disabled. The set of enabled variants is
+        remembered from when the project is configured.
+
+      -f FILE
+        Use FILE as Rsconscript.
+
+      -F, --show-failure
+        Show failed command log from previous build and exit (does not load build
+        script).
+
+      -h, --help
+        Show rscons help and exit (does not load build script).
+
+      -j N, --nthreads=N
+        Set number of threads (local default: 16).
+
+      -r COLOR, --color=COLOR
+        Set color mode (off, auto, force).
+
+      -T, --tasks
+        Show task list and parameters and exit (loads build script). By default
+        only tasks with a description are listed. Use -AT to show all tasks whether
+        they have a description or not.
+
+      -v, --verbose
+        Run verbosely. This causes Rscons to print the full build command used by
+        each builder.
+
+      --version
+        Show rscons version and exit (does not load build script).
 
 The user can list any number of tasks on the command line.
 Any parameters beginning with a "-" that follow a task are interpreted as task
@@ -190,9 +222,9 @@ will cause Rscons to print each command it is executing.
 When Rscons executes, it performs the following phases:
 
   - Parse the command line.
-    - Exit if --help or --version specified.
+    - This is the last step if --help, --version, or --show-failure is specified.
   - Load the build script.
-    - Show tasks and exit if -T specified.
+    - This is the last step if --tasks is specified.
   - Configure the project by running the `configure` task if necessary (the
     project has not yet been configured, autoconf is set to true, and the user
     is requesting to execute a task that is marked with autoconf set to true)
diff --git a/lib/rscons/cli.rb b/lib/rscons/cli.rb
index 87369b2..478984f 100644
--- a/lib/rscons/cli.rb
+++ b/lib/rscons/cli.rb
@@ -149,17 +149,49 @@ module Rscons
 Usage: #{$0} [global options] [[task] [task options] ...]
 
 Global options:
-  -A, --all                   Show all tasks (even without descriptions) in task list
-  -b BUILD, --build=BUILD     Set build directory (default: build)
-  -e VS, --variants=VS        Enable or disable variants
-  -f FILE                     Use FILE as Rsconscript
-  -F, --show-failure          Show failed command log from previous build and exit
-  -h, --help                  Show rscons help and exit
-  -j N, --nthreads=N          Set number of threads (local default: #{Rscons.application.n_threads})
-  -r COLOR, --color=COLOR     Set color mode (off, auto, force)
-  -T, --tasks                 Show task list and parameters and exit
-  -v, --verbose               Run verbosely
-  --version                   Show rscons version and exit
+  -A, --all
+    Show all tasks (even those without descriptions) in task list. Use in
+    conjunction with the -T argument.
+
+  -b BUILD, --build=BUILD
+    Set build directory (default: build).
+
+  -e VS, --variants=VS
+    Enable or disable variants. VS is a comma-separated list of variant
+    entries. If the entry begins with "-" the variant is disabled instead of
+    enabled. If the full list begins with "+" or "-" then it modifies the
+    variants that are enabled by default by only enabling or disabling the
+    listed variants. Otherwise, the enabled set of variants is as given and
+    any variants not listed are disabled. The set of enabled variants is
+    remembered from when the project is configured.
+
+  -f FILE
+    Use FILE as Rsconscript.
+
+  -F, --show-failure
+    Show failed command log from previous build and exit (does not load build
+    script).
+
+  -h, --help
+    Show rscons help and exit (does not load build script).
+
+  -j N, --nthreads=N
+    Set number of threads (local default: #{Rscons.application.n_threads}).
+
+  -r COLOR, --color=COLOR
+    Set color mode (off, auto, force).
+
+  -T, --tasks
+    Show task list and parameters and exit (loads build script). By default
+    only tasks with a description are listed. Use -AT to show all tasks whether
+    they have a description or not.
+
+  -v, --verbose
+    Run verbosely. This causes Rscons to print the full build command used by
+    each builder.
+
+  --version
+    Show rscons version and exit (does not load build script).
 EOF
     end