diff --git a/functions/bool_to_yesno.pp b/functions/bool_to_yesno.pp
index cbae86fee8e4a8d306218fb619d3d4c4fb7631ce..3a84c8b3e86c5f1e0986c90f219903ef141eac89 100644
--- a/functions/bool_to_yesno.pp
+++ b/functions/bool_to_yesno.pp
@@ -1,3 +1,7 @@
+# Converts a boolean to a yes/no string
+# @param bool
+#   The boolean to convertt
+# @return the string 'yes' or 'no'
 function mpd::bool_to_yesno (
   Boolean $bool,
 ) >> String {
diff --git a/types/metadata.pp b/types/metadata.pp
index c85f3e58adf8eab713dd0f76e9ff9ec4e3cfd186..c8b365f5f81f13b9d6269b8e334a86a6b21920ff 100644
--- a/types/metadata.pp
+++ b/types/metadata.pp
@@ -1,3 +1,4 @@
+# Types of MPD metadata
 type Mpd::Metadata = Variant[
   Enum['none'],
   Array[Enum[
diff --git a/types/password.pp b/types/password.pp
index 35da590b99307d0864c433b8034cfeeb42ebb81c..3974c0e68013754b210f4abacfbc0c9b6f99bf7f 100644
--- a/types/password.pp
+++ b/types/password.pp
@@ -1 +1,7 @@
-type Mpd::Password = Struct[{ name => String, permissions => Array[Mpd::Permission] }]
+# An MPD user
+# Name is the password of the user
+# Permissions is what the user is allowed to do
+type Mpd::Password = Struct[{
+  name => String,
+  permissions => Array[Mpd::Permission]
+}]
diff --git a/types/permission.pp b/types/permission.pp
index 3856b7c225fe4f1acbedf3e2adfc8f973e538455..f0f24653dd41045f3769cb76b11165ec6a398110 100644
--- a/types/permission.pp
+++ b/types/permission.pp
@@ -1 +1,2 @@
+# Available MPD permissions
 type Mpd::Permission = Enum['read', 'add', 'control', 'admin']