diff --git a/lib/System/Nagios/Plugin/Ekg.hs b/lib/System/Nagios/Plugin/Ekg.hs
--- a/lib/System/Nagios/Plugin/Ekg.hs
+++ b/lib/System/Nagios/Plugin/Ekg.hs
@@ -1,3 +1,13 @@
+{-|
+Module      : Nagios.Plugin.Ekg
+Copyright   : Sharif Olorin, 2015, 
+              Anchor Systems, 2015
+License     : MIT
+Maintainer  : Sharif Olorin <sio@tesser.org>
+Stability   : experimental
+Portability : POSIX
+-}
+
 module System.Nagios.Plugin.Ekg (
     module System.Nagios.Plugin.Ekg.Check,
     module System.Nagios.Plugin.Ekg.Types
diff --git a/lib/System/Nagios/Plugin/Ekg/Check.hs b/lib/System/Nagios/Plugin/Ekg/Check.hs
--- a/lib/System/Nagios/Plugin/Ekg/Check.hs
+++ b/lib/System/Nagios/Plugin/Ekg/Check.hs
@@ -1,6 +1,9 @@
 {-# LANGUAGE OverloadedStrings #-}
 
-module System.Nagios.Plugin.Ekg.Check where
+module System.Nagios.Plugin.Ekg.Check (
+    checkEkg,
+    checkEkg'
+) where
 
 import Control.Applicative
 import Control.Lens
@@ -16,6 +19,9 @@
 
 import System.Nagios.Plugin.Ekg.Types
 
+data PluginOpts = PluginOpts
+  { optsEndpoint :: String }
+
 pluginOptParser :: ParserInfo PluginOpts
 pluginOptParser =  info (helper <*> opts)
     (   fullDesc
@@ -30,6 +36,11 @@
                                      <> help "URL of the EKG endpoint."
                                     )
 
+-- | Run the check against the EKG endpoint specified on the command
+--   line. Terminate according to the
+--   <https://nagios-plugins.org/doc/guidelines.html#PLUGOUTPUT plugin development guidelines> -
+--   'OK' if we retrieve and successfully parse a result, otherwise
+--   'CRITICAL'.
 checkEkg :: NagiosPlugin ()
 checkEkg = do
     opts <- liftIO $ execParser pluginOptParser
@@ -39,6 +50,8 @@
         200 -> checkEkg' $ resp ^. responseBody
         code -> addResult Critical . T.pack $ "EKG endpoint failed with status " <> show code
 
+-- | Version of 'checkEkg' which takes a 'ByteString' rather than
+--   requesting it from an EKG endpoint.
 checkEkg' :: ByteString -> NagiosPlugin ()
 checkEkg' bs = case (eitherDecode' bs :: Either String MetricTree) of
     Left err -> addResult Critical $ "failed to parse EKG output: " <> T.pack err
diff --git a/lib/System/Nagios/Plugin/Ekg/Types.hs b/lib/System/Nagios/Plugin/Ekg/Types.hs
--- a/lib/System/Nagios/Plugin/Ekg/Types.hs
+++ b/lib/System/Nagios/Plugin/Ekg/Types.hs
@@ -1,6 +1,8 @@
 {-# LANGUAGE OverloadedStrings #-}
 
-module System.Nagios.Plugin.Ekg.Types where
+module System.Nagios.Plugin.Ekg.Types (
+    MetricTree
+) where
 
 import Control.Applicative
 import Control.Monad
@@ -16,17 +18,14 @@
 import qualified Data.Text as T
 import System.Nagios.Plugin
 
-data PluginOpts = PluginOpts
-  { optsEndpoint :: String }
-
 data EkgMetric =
-     -- * Nondecreasing counter, e.g., all-time number of requests.
+     -- | Nondecreasing counter, e.g., all-time number of requests.
       EkgCounter Int64
-     -- * Measure of a quantity over time, e.g., number of requests per minute.
+     -- | Measure of a quantity over time, e.g., number of requests per minute.
     | EkgGauge Double
-    -- * Can't meaningfully turn labels into perfdata, this is a placeholder.
+     -- | Can't meaningfully turn labels into perfdata, this is a placeholder.
     | EkgLabel
-    -- * Can't meaningfully turn distributions into perfdata, this is a placeholder.
+     -- | Can't meaningfully turn distributions into perfdata, this is a placeholder.
     | EkgDistribution
   deriving (Eq, Show)
 
@@ -66,6 +65,9 @@
             )
     parseJSON x          = fail $ "MetricNode must be an object, not " <> show x
 
+-- | Top-level object for parsed EKG metrics. Structurally, this is an
+--   n-ary tree; the leaves are the metrics themselves and the
+--   non-leaf nodes are used to construct the metric labels.
 newtype MetricTree = MetricTree
     { unMetricTree :: Map Text MetricNode }
 
diff --git a/nagios-plugin-ekg.cabal b/nagios-plugin-ekg.cabal
--- a/nagios-plugin-ekg.cabal
+++ b/nagios-plugin-ekg.cabal
@@ -1,5 +1,5 @@
 name:                nagios-plugin-ekg
-version:             0.1.0.0
+version:             0.1.1.0
 synopsis:            Monitor ekg metrics via Nagios
 description:         A generic Nagios plugin which retrieves metrics
                      from an application which uses