diff --git a/lib/rackstash/message.rb b/lib/rackstash/message.rb
index 2f45736..8aa3503 100644
--- a/lib/rackstash/message.rb
+++ b/lib/rackstash/message.rb
@@ -8,23 +8,43 @@
 require 'rackstash/helpers'
 
 module Rackstash
-  # This class and all its data are immutable after initialization
+  # A Message wraps a single logged message created by the {Logger}. Here, we
+  # store the formatted message itself plus some additional meta-data about the
+  # message.
+  #
+  # In the end, only the `message` field will be included in the final log
+  # event. However, the stored meta-data can be useful when filtering or
+  # changing the messages of a log event using {Filters} later.
+  #
+  # All `Message` objects and their respective data are immutable after
+  # initialization.
   class Message
     include Rackstash::Helpers::UTF8
 
+    # @return [String] the logged message string. It usually is already
+    #   formatted by the {Logger}'s formatter
     attr_reader :message
-
     alias as_json message
-    # Messages are implicitly conversible to Strings
     alias to_s message
     alias to_str message
 
+    # @return [Integer] the numeric severity of the logged message. Usually
+    #   corresponds to one of the {SEVERITIES} constants
     attr_reader :severity
 
+    # @return [String] the progname provided (or inferred) during logging of the
+    #   message by the {Logger}.
     attr_reader :progname
 
+    # @return [Time] the frozen timestamp of the logged message. While this
+    #   timestamp is usually in UTC, it is not guaranteed.
     attr_reader :time
 
+    # @param message [String, #inspect] a message string
+    # @param severity [Integer] the numeric severity of the logged message
+    # @param time [Time] the timestamp of the logged message
+    # @param progname [String] the progname provided (or inferred) during
+    #   logging of the message by the {Logger}.
     def initialize(message, severity: UNKNOWN, time: Time.now.utc.freeze, progname: PROGNAME)
       @severity = Integer(severity)
       @severity = 0 if @severity < 0
@@ -36,7 +56,7 @@ module Rackstash
     end
 
     # @return [String] the guman readable label for the {#severity}.
-    # @see {Rackstash.severity_label}
+    # @see Rackstash.severity_label
     def severity_label
       Rackstash.severity_label(@severity)
     end
@@ -47,16 +67,17 @@ module Rackstash
     end
     alias size length
 
+    # @return [String] A JSON representation of the message string
     def to_json
       as_json.to_json
     end
 
     private
 
-    # Sanitize a single mesage to be added to the buffer, can be a single or
-    # multi line string
+    # Cleanup the message.
     #
-    # @param msg [String, #inspect] a message to be added to the buffer
+    # @param msg [String, #inspect] A message string. If anything else than
+    #   a `String`, we will inspect it.
     # @return [String] the sanitized frozen message
     def cleanup(msg)
       msg = msg.inspect unless msg.is_a?(String)