feat: add separate YouTube Shorts descriptions

app/Actions/Post/UpdatePost.php

@@ -12,6 +12,7 @@
 use App\Models\Post;
 use App\Models\PostPlatform;
 use App\Models\Workspace;
+use App\Support\PostPlatformMetaRules;
 use App\Support\PostStatusRules;
 use App\Support\Social\AbandonGoogleBusinessReview;
 use App\Support\Social\GoogleBusinessDerivativeCleaner;
@@ -74,7 +75,16 @@ public static function execute(Workspace $workspace, Post $post, array $data): a
                         ->where('id', data_get($platformData, 'id'))
                         ->update($updateData);
                 }
+            }
+
+            if (in_array($post->status, [PostStatus::Scheduled, PostStatus::Publishing], true)) {
+                PostPlatformMetaRules::assertStoredPostPublishable(
+                    $post,
+                    collect(data_get($data, 'platforms', []))->pluck('id')->all(),
+                );
+            }
 
+            if (Arr::has($data, 'platforms')) {
                 $post->postPlatforms()
                     ->disabled()
                     ->where('platform', Platform::GoogleBusiness)

app/Enums/SocialAccount/Platform.php

@@ -164,10 +164,10 @@ public function supportsAltText(): bool
      *  - LinkedIn UGC: 3000 (`commentary` field)
      *  - X standard tweet: 280 (X Premium accepts 25K — ignored, conservative)
      *  - TikTok caption: 2200
-     *  - YouTube Shorts: title=100, description=5000. We feed `content` to both
-     *    (publisher derives title from the first line via `buildTitle`), and
-     *    Shorts UX only shows ~100 chars before "more" — capping at 100 keeps
-     *    posts appropriate for the format.
+     *  - YouTube Shorts: content supplies the title, capped at 100 characters
+     *    (publisher derives it from the first line via `buildTitle`). Optional
+     *    meta.description is separate plain text, capped at 5000 UTF-8 bytes;
+     *    absent descriptions fall back to content.
      *  - Facebook text status: 10000 (API allows 63206; we cap below
      *    that — 63k-char posts are unrealistic and emoji-heavy content
      *    risks overflowing the TEXT column's 65535-byte ceiling)

app/Mcp/Tools/Post/CreatePostTool.php

@@ -79,7 +79,7 @@ public function schema(JsonSchema $schema): array
                 ->items($schema->object(fn ($p) => [
                     'social_account_id' => $p->string()->required()->description('UUID of the connected social account.'),
                     'content_type' => $p->string()->required()->description('Format for this platform (e.g. linkedin_post, x_post, instagram_feed).'),
-                    'meta' => $p->object()->description('Per-platform metadata. Instagram/Facebook: aspect_ratio (1:1|4:5|16:9|original). TikTok: privacy_level PUBLIC_TO_EVERYONE|MUTUAL_FOLLOW_FRIENDS|FOLLOWER_OF_CREATOR|SELF_ONLY (required to publish) + flags (allow_comments, allow_duet, allow_stitch, disclose, brand_content_toggle, brand_organic_toggle, is_aigc, auto_add_music). SELF_ONLY cannot be combined with brand_content_toggle. Pinterest: board_id (required to publish — call ListPinterestBoardsTool first), title (≤100), link (destination URL). Pin description comes from the post content. Discord: channel_id (required to publish — call ListDiscordChannelsTool first), mentions ([{token,label}]), embeds ([{title,description,url,image,color}]).'),
+                    'meta' => $p->object()->description('Per-platform metadata. Instagram/Facebook: aspect_ratio (1:1|4:5|16:9|original). TikTok: privacy_level PUBLIC_TO_EVERYONE|MUTUAL_FOLLOW_FRIENDS|FOLLOWER_OF_CREATOR|SELF_ONLY (required to publish) + flags (allow_comments, allow_duet, allow_stitch, disclose, brand_content_toggle, brand_organic_toggle, is_aigc, auto_add_music). SELF_ONLY cannot be combined with brand_content_toggle. Pinterest: board_id (required to publish — call ListPinterestBoardsTool first), title (≤100), link (destination URL). Pin description comes from the post content. Discord: channel_id (required to publish — call ListDiscordChannelsTool first), mentions ([{token,label}]), embeds ([{title,description,url,image,color}]). YouTube Shorts: description (optional plain text, at most 5000 bytes). Post content remains the title source, limited to 100 characters. Omit description or pass null to use the post content as description.'),
                 ]))
                 ->description('Platforms to publish on. Accounts not listed remain available but disabled.'),
         ];

app/Mcp/Tools/Post/UpdatePostTool.php

@@ -119,7 +119,7 @@ public function schema(JsonSchema $schema): array
                 ->items($schema->object(fn ($p) => [
                     'id' => $p->string()->required()->description('UUID of the post_platform row (from get-post-tool / list-posts-tool).'),
                     'content_type' => $p->string()->description('New content_type for this platform.'),
-                    'meta' => $p->object()->description('Per-platform metadata override. Instagram/Facebook: aspect_ratio. TikTok: privacy_level PUBLIC_TO_EVERYONE|MUTUAL_FOLLOW_FRIENDS|FOLLOWER_OF_CREATOR|SELF_ONLY (required to publish) + flags. SELF_ONLY cannot be combined with brand_content_toggle. Pinterest: board_id (required to publish — call ListPinterestBoardsTool first), title (≤100), link (destination URL). Pin description comes from the post content. Discord: channel_id (required to publish — call ListDiscordChannelsTool first), mentions, embeds. Merged with existing meta.'),
+                    'meta' => $p->object()->description('Per-platform metadata override. Instagram/Facebook: aspect_ratio. TikTok: privacy_level PUBLIC_TO_EVERYONE|MUTUAL_FOLLOW_FRIENDS|FOLLOWER_OF_CREATOR|SELF_ONLY (required to publish) + flags. SELF_ONLY cannot be combined with brand_content_toggle. Pinterest: board_id (required to publish — call ListPinterestBoardsTool first), title (≤100), link (destination URL). Pin description comes from the post content. Discord: channel_id (required to publish — call ListDiscordChannelsTool first), mentions, embeds. Merged with existing meta. YouTube Shorts: description (optional plain text, at most 5000 bytes). Post content remains the title source, limited to 100 characters. Omit description to keep the current override; pass null to remove it and use the post content as description.'),
                 ]))
                 ->description('Platforms to enable for publishing. Any platform NOT listed will be disabled. Pass an empty array to disable all.'),
         ];

app/Rules/ValidYouTubeDescription.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Rules;
+
+use App\Support\YouTubeDescription;
+use Closure;
+use Illuminate\Contracts\Validation\ValidationRule;
+use Illuminate\Translation\PotentiallyTranslatedString;
+
+class ValidYouTubeDescription implements ValidationRule
+{
+    /**
+     * @param  Closure(string, ?string=): PotentiallyTranslatedString  $fail
+     */
+    public function validate(string $attribute, mixed $value, Closure $fail): void
+    {
+        $key = YouTubeDescription::violation($value);
+
+        if ($key !== null) {
+            $fail($key)->translate();
+        }
+    }
+}

app/Services/Post/PostPreviewer.php

@@ -4,9 +4,11 @@
 
 namespace App\Services\Post;
 
+use App\Enums\SocialAccount\Platform;
 use App\Models\Post;
 use App\Models\PostPlatform;
 use App\Services\Social\ContentSanitizer;
+use App\Support\YouTubeDescription;
 use Illuminate\Support\Collection;
 
 /**
@@ -31,7 +33,9 @@ public function __construct(private readonly ContentSanitizer $sanitizer) {}
      *         sanitized_content: string,
      *         sanitized_length: int,
      *         max_content_length: int,
-     *         truncated: bool
+     *         truncated: bool,
+     *         description?: string,
+     *         description_length_bytes?: int
      *     }>
      * }
      */
@@ -59,7 +63,7 @@ private function platformPreviews(Post $post, string $original): Collection
                 $platform = $pp->socialAccount?->platform ?? $pp->platform;
                 $sanitized = $this->sanitizer->sanitize($original, $platform);
 
-                return [
+                $preview = [
                     'post_platform_id' => $pp->id,
                     'platform' => $platform->value,
                     'content_type' => $pp->content_type?->value,
@@ -68,6 +72,14 @@ private function platformPreviews(Post $post, string $original): Collection
                     'max_content_length' => $platform->maxContentLength(),
                     'truncated' => mb_strlen($sanitized) < mb_strlen($original),
                 ];
+
+                if ($platform === Platform::YouTube) {
+                    $description = YouTubeDescription::resolve($pp->meta, $sanitized);
+                    $preview['description'] = $description;
+                    $preview['description_length_bytes'] = strlen($description);
+                }
+
+                return $preview;
             });
     }
 }