diff --git a/lib/github_changelog_generator/options.rb b/lib/github_changelog_generator/options.rb
index 70fa3d6..2d73caa 100644
--- a/lib/github_changelog_generator/options.rb
+++ b/lib/github_changelog_generator/options.rb
@@ -2,9 +2,14 @@
 
 require "delegate"
 module GitHubChangelogGenerator
+  # This class wraps Options, and knows a list of known options. Others options
+  # will raise exceptions.
   class Options < SimpleDelegator
+    # Raised on intializing with unknown keys in the values hash,
+    # and when trying to store a value on an unknown key.
     UnsupportedOptionError = Class.new(ArgumentError)
 
+    # List of valid option names
     KNOWN_OPTIONS = %i[
       add_issues_wo_labels
       add_pr_wo_labels
@@ -56,23 +61,31 @@ module GitHubChangelogGenerator
       verbose
     ]
 
+    # @param values [Hash]
+    #
+    # @raise [UnsupportedOptionError] if given values contain unknown options
     def initialize(values)
       super(values)
       unsupported_options.any? && raise(UnsupportedOptionError, unsupported_options.inspect)
     end
 
+    # Set option key to val.
+    #
+    # @param key [Symbol]
+    # @param val [Object]
+    #
+    # @raise [UnsupportedOptionError] when trying to set an unknown option
     def []=(key, val)
       supported_option?(key) || raise(UnsupportedOptionError, key.inspect)
       values[key] = val
     end
 
+    # @return [Hash]
     def to_hash
       values
     end
 
     # Loads the configured Ruby files from the --require option.
-    #
-    # @return [void]
     def load_custom_ruby_files
       self[:require].each { |f| require f }
     end
diff --git a/lib/github_changelog_generator/parser.rb b/lib/github_changelog_generator/parser.rb
index 9c8cf88..747e3d9 100755
--- a/lib/github_changelog_generator/parser.rb
+++ b/lib/github_changelog_generator/parser.rb
@@ -5,6 +5,7 @@ require "optparse"
 require "pp"
 require_relative "version"
 require_relative "helper"
+
 module GitHubChangelogGenerator
   class Parser
     # parse options with optparse
@@ -26,23 +27,23 @@ module GitHubChangelogGenerator
       options
     end
 
-    # If options set to verbose, print the parsed options.
+    # Pretty-print the parsed options.
     #
     # The GitHub `:token` key is censored in the output.
     #
-    # @param options [Hash] The options to display
+    # @param options [Options] The options to display
     # @option options [Boolean] :verbose If false this method does nothing
     def self.print_options(options)
-      if options[:verbose]
-        Helper.log.info "Performing task with options:"
-        options_to_display = options.clone
-        options_to_display[:token] = options_to_display[:token].nil? ? nil : "hidden value"
-        pp options_to_display
-        puts ""
-      end
+      return unless options[:verbose]
+
+      Helper.log.info "Using these options:"
+      pp(options.clone.tap { |opts| opts[:token] = opts[:token].nil? ? "No token used" : "hidden value" })
+      puts ""
     end
 
-    # setup parsing options
+    # Setup parsing options
+    #
+    # @param options [Options]
     def self.setup_parser(options)
       parser = OptionParser.new do |opts| # rubocop:disable Metrics/BlockLength
         opts.banner = "Usage: github_changelog_generator [options]"
@@ -199,7 +200,7 @@ module GitHubChangelogGenerator
       parser
     end
 
-    # @return [Hash] Default options
+    # @return [Options] Default options
     def self.default_options
       Options.new(
         date_format: "%Y-%m-%d",