diff --git a/actionpack/lib/action_controller/metal/strong_parameters.rb b/actionpack/lib/action_controller/metal/strong_parameters.rb
index 3b293baa73ea7f04d1a0f65e6b84ff8fa55682a3..563c3c0e59b00ebd1104e8fdc3f93922fe8bbe5f 100644
--- a/actionpack/lib/action_controller/metal/strong_parameters.rb
+++ b/actionpack/lib/action_controller/metal/strong_parameters.rb
@@ -112,6 +112,77 @@ class Parameters
 
     cattr_accessor :action_on_unpermitted_parameters, instance_accessor: false
 
+    ##
+    # :method: as_json
+    #
+    # :call-seq:
+    #   as_json(options=nil)
+    #
+    # Returns a hash that can be used as the JSON representation for the params.
+
+    ##
+    # :method: empty?
+    #
+    # :call-seq:
+    #   empty?()
+    #
+    # Returns true if the object has no key/value pairs.
+
+    ##
+    # :method: has_key?
+    #
+    # :call-seq:
+    #   has_key?(key)
+    #
+    # Returns true if the given key is present in the parameters.
+
+    ##
+    # :method: has_value?
+    #
+    # :call-seq:
+    #   has_value?(value)
+    #
+    # Returns true if the given value is present for some key in the parameters.
+
+    ##
+    # :method: include?
+    #
+    # :call-seq:
+    #   include?(key)
+    #
+    # Returns true if the given key is present in the parameters.
+
+    ##
+    # :method: key?
+    #
+    # :call-seq:
+    #   key?(key)
+    #
+    # Returns true if the given key is present in the parameters.
+
+    ##
+    # :method: keys
+    #
+    # :call-seq:
+    #   keys()
+    #
+    # Returns a new array of the keys of the parameters.
+
+    ##
+    # :method: value?
+    #
+    # :call-seq:
+    #   value?(value)
+    #
+    # Returns true if the given value is present for some key in the parameters.
+
+    ##
+    # :method: values
+    #
+    # :call-seq:
+    #   values()
+    #
+    # Returns a new array of the values of the parameters.
     delegate :keys, :key?, :has_key?, :values, :has_value?, :value?, :empty?, :include?,
       :as_json, to: :@parameters