parameter_list was meant here

Doc/reference/compound_stmts.rst

@@ -427,7 +427,7 @@ A function definition defines a user-defined function object (see section
 .. productionlist::
    funcdef: [`decorators`] "def" `funcname` "(" [`parameter_list`] ")" ["->" `expression`] ":" `suite`
    decorators: `decorator`+
-   decorator: "@" `dotted_name` ["(" [`argument_list` [","]] ")"] NEWLINE
+   decorator: "@" `dotted_name` ["(" [`parameter_list` [","]] ")"] NEWLINE
    dotted_name: `identifier` ("." `identifier`)*
    parameter_list: (`defparameter` ",")*
                  : (  "*" [`parameter`] ("," `defparameter`)*