diff --git a/src/consts.ts b/src/consts.ts
index 074a9fb..e68d105 100644
--- a/src/consts.ts
+++ b/src/consts.ts
@@ -2,5 +2,7 @@ export const SITE_TITLE = 'SHIFTBRAIN Playground'
 export const SITE_LANG = 'ja'
 export const SITE_REGION = 'JP'
 export const SITE_TWITTER_ID = 'SHIFTBRAIN'
+export const SITE_DESCRIPTION =
+  'SHIFTBRAIN Playgroundは、技術力向上のために日々行われている実験や試作を公開するサイトです。'
 
 export const authors = ['kaminaly', 'heo', 'ikurumi', 'sato', 'kiyose', 'komakine'] as const
diff --git a/src/layouts/Layout.astro b/src/layouts/Layout.astro
index f7a99fc..6299ae5 100644
--- a/src/layouts/Layout.astro
+++ b/src/layouts/Layout.astro
@@ -1,6 +1,6 @@
 ---
 import defaultOpenGraphImage from '../assets/opengraph-image.png'
-import { SITE_LANG, SITE_REGION, SITE_TITLE, SITE_TWITTER_ID } from '../consts'
+import { SITE_LANG, SITE_REGION, SITE_TITLE, SITE_TWITTER_ID, SITE_DESCRIPTION } from '../consts'
 import Header from './Header.astro'
 
 interface Props {
@@ -42,7 +42,7 @@ const canonicalURL: URL = new URL(Astro.url.pathname, Astro.site)
       gtag('config', 'G-NZ6C341T6V')
     </script>
 
-    {description && <meta name="description" content={description} />}
+    <meta name="description" content={description || SITE_DESCRIPTION} />
     <meta name="twitter:card" content="summary_large_image" />
     <meta name="twitter:site" content={`@${SITE_TWITTER_ID}`} />
     <meta name="twitter:title" content={pageTitle} />
@@ -51,7 +51,7 @@ const canonicalURL: URL = new URL(Astro.url.pathname, Astro.site)
     <meta property="og:type" content="website" />
     <meta property="og:image" content={resolvedOgImage} />
     {canonicalURL && <meta property="og:url" content={canonicalURL} />}
-    {description && <meta property="og:description" content={description} />}
+    <meta property="og:description" content={description || SITE_DESCRIPTION} />
     <meta property="og:site_name" content={SITE_TITLE} />
     <meta property="og:locale" content={`${SITE_LANG}_${SITE_REGION}`} />