diff --git a/devbox.json b/devbox.json
index 46eb1ad..a19fc67 100644
--- a/devbox.json
+++ b/devbox.json
@@ -12,6 +12,7 @@
       ],
       "format": "prettier -w \"**/*.{js,mjs}\"",
       "format:check": "prettier -c \"**/*.{js,mjs}\"",
+      "doc:preview": "npx -y --package gren-packages gren-doc-preview",
       "test": [
         "devbox run test:unit",
         "devbox run test:integration"
diff --git a/src/Cli/Parser.gren b/src/Cli/Parser.gren
index e32c4db..658946b 100644
--- a/src/Cli/Parser.gren
+++ b/src/Cli/Parser.gren
@@ -285,6 +285,13 @@ prefixHelpText appName prefixName (GroupParser { knownCommands }) =
 
 
 {-| Definition of a command.
+
+* `word` is the name of the command, like `make` in `gren make`.
+* `arguments` and `flags` parse the command's inputs, which will be passed to `builder`.
+* `commonDescription`, if set, will include the command along with this description in the list of "commonly used" commands shown in the program's usage help text.
+* `summary` is the short description of the command, shown at the top of the command's help text.
+* `example` is the longer description and/or example(s) of using the command. It comes after `summary` in the command help text.
+* `builder` combines the parsed arguments and flags into a `result`
 -}
 type alias Command args flags result =
     { word : String