diff --git a/web/src/components/GenerationCard.tsx b/web/src/components/GenerationCard.tsx
index 8d16575..d618817 100644
--- a/web/src/components/GenerationCard.tsx
+++ b/web/src/components/GenerationCard.tsx
@@ -173,7 +173,10 @@ export function GenerationCard({ task, onOpenDetail }: Props) {
     const style = getComputedStyle(container);
     const font = `${style.fontSize} ${style.fontFamily}`;
     const labelsWidth = labelsEl.offsetWidth + 8;
-    const totalAvailable = containerWidth * 2 - labelsWidth - 24;
+    // Account for mention tags (thumbnails) taking extra width vs plain text
+    const mentionCount = (task.assetMentions?.length || 0) + (task.references?.length || 0);
+    const mentionExtraWidth = mentionCount * 24; // ~24px extra per mention (thumbnail + padding)
+    const totalAvailable = containerWidth * 2 - labelsWidth - 24 - mentionExtraWidth;
 
     const canvas = document.createElement('canvas');
     const ctx = canvas.getContext('2d')!;