diff --git a/META.json b/META.json
index 2642872..4c49375 100644
--- a/META.json
+++ b/META.json
@@ -1,10 +1,10 @@
 {
-   "abstract" : "It's new $module",
+   "abstract" : "assert keyword for Perl",
    "author" : [
       "kobaken <kentafly88@gmail.com>"
    ],
    "dynamic_config" : 0,
-   "generated_by" : "Minilla/v3.1.24, CPAN::Meta::Converter version 2.150010",
+   "generated_by" : "Minilla/v3.1.25, CPAN::Meta::Converter version 2.150010",
    "license" : [
       "perl_5"
    ],
diff --git a/README.md b/README.md
index 45464d2..cdd4726 100644
--- a/README.md
+++ b/README.md
@@ -1,15 +1,30 @@
 [![Actions Status](https://github.com/kfly8/Syntax-Keyword-Assert/actions/workflows/test.yml/badge.svg)](https://github.com/kfly8/Syntax-Keyword-Assert/actions)
 # NAME
 
-Syntax::Keyword::Assert - It's new $module
+Syntax::Keyword::Assert - assert keyword for Perl
 
 # SYNOPSIS
 
     use Syntax::Keyword::Assert;
 
+    sub hello($name) {
+        assert { defined $name };
+        say "Hello, $name!";
+    }
+
+    hello("Alice"); # => Hello, Alice!
+    hello();        # => Dies when STRICT_MODE is enabled
+
 # DESCRIPTION
 
-Syntax::Keyword::Assert is ...
+This module provides a syntax plugin that introduces an **assert** keyword to Perl.
+It dies when the block returns false and `STRICT` mode is enabled. When `STRICT` mode is disabled, the block is ignored at compile time. The syntax is simple, `assert BLOCK`.
+
+`STRICT` mode is controlled by [Devel::StrictMode](https://metacpan.org/pod/Devel%3A%3AStrictMode).
+
+# SEE ALSO
+
+[PerlX::Assert](https://metacpan.org/pod/PerlX%3A%3AAssert), [Devel::Assert](https://metacpan.org/pod/Devel%3A%3AAssert), [Carp::Assert](https://metacpan.org/pod/Carp%3A%3AAssert)
 
 # LICENSE
 
diff --git a/lib/Syntax/Keyword/Assert.pm b/lib/Syntax/Keyword/Assert.pm
index 7dc2429..14360ec 100644
--- a/lib/Syntax/Keyword/Assert.pm
+++ b/lib/Syntax/Keyword/Assert.pm
@@ -49,15 +49,30 @@ __END__
 
 =head1 NAME
 
-Syntax::Keyword::Assert - It's new $module
+Syntax::Keyword::Assert - assert keyword for Perl
 
 =head1 SYNOPSIS
 
     use Syntax::Keyword::Assert;
 
+    sub hello($name) {
+        assert { defined $name };
+        say "Hello, $name!";
+    }
+
+    hello("Alice"); # => Hello, Alice!
+    hello();        # => Dies when STRICT_MODE is enabled
+
 =head1 DESCRIPTION
 
-Syntax::Keyword::Assert is ...
+This module provides a syntax plugin that introduces an B<assert> keyword to Perl.
+It dies when the block returns false and C<STRICT> mode is enabled. When C<STRICT> mode is disabled, the block is ignored at compile time. The syntax is simple, C<assert BLOCK>.
+
+C<STRICT> mode is controlled by L<Devel::StrictMode>.
+
+=head1 SEE ALSO
+
+L<PerlX::Assert>, L<Devel::Assert>, L<Carp::Assert>
 
 =head1 LICENSE