KAN-73: document and validate MCP ticket description format

app/Mcp/Tools/UpdateTicketDescription.php

@@ -2,10 +2,14 @@
 
 namespace App\Mcp\Tools;
 
+use App\Actions\Tickets\Support\TicketDescriptionFormat;
 use App\Actions\Tickets\UpdateProjectTicket;
+use App\Mcp\Support\DescribesTicketWriting;
 use App\Mcp\Support\KanbanGitMcp;
+use App\Rules\VisualTicketDescription;
 use Illuminate\Contracts\JsonSchema\JsonSchema;
 use Illuminate\JsonSchema\Types\Type;
+use Illuminate\Support\Arr;
 use Laravel\Mcp\Request;
 use Laravel\Mcp\Response;
 use Laravel\Mcp\ResponseFactory;
@@ -19,6 +23,8 @@ use Laravel\Mcp\Server\Tools\Annotations\IsDestructive;
 #[IsDestructive(false)]
 class UpdateTicketDescription extends Tool
 {
+    use DescribesTicketWriting;
+
     public function __construct(
         private readonly KanbanGitMcp $kanbanGitMcp,
         private readonly UpdateProjectTicket $updateProjectTicket,
@@ -27,7 +33,7 @@ class UpdateTicketDescription extends Tool
     public function handle(Request $request): Response|ResponseFactory
     {
         $validated = $request->validate([
-            'description' => ['nullable', 'string'],
+            'description' => ['nullable', 'string', new VisualTicketDescription],
             'ticket_id' => ['required', 'integer'],
         ]);
 
@@ -35,7 +41,7 @@ class UpdateTicketDescription extends Tool
         $ticket = $this->kanbanGitMcp->ticketForWrite($user, (int) $validated['ticket_id']);
         $payload = [
             ...$this->kanbanGitMcp->updatePayload($ticket),
-            'description' => $validated['description'] ?? null,
+            ...(Arr::exists($validated, 'description') ? ['description' => Arr::get($validated, 'description')] : []),
         ];
 
         $wasUpdated = $this->updateProjectTicket->handle($ticket, $user, $payload);
@@ -58,7 +64,7 @@ class UpdateTicketDescription extends Tool
         return [
             'description' => $schema->string()
                 ->nullable()
-                ->description('New ticket description. Pass null to clear it.'),
+                ->description('New ticket description. Omit to preserve; pass null to clear it. '.TicketDescriptionFormat::instructions()),
             'ticket_id' => $schema->integer()
                 ->description('Ticket ID.')
                 ->required(),