Here are a few options for a WordPress post tag description for “線上訂票” (Online Booking) in Traditional Chinese, ranging from concise to more explanatory:

**Option 1: Concise & Direct**

* **Description:** 快速、方便的線上訂票服務。 (Fast and convenient online booking service.)

**Option 2: Slightly More Informative**

* **Description:** 瀏覽、比較並線上預訂各種活動、交通票券和其他服務。 (Browse, compare, and book various events, transportation tickets, and other services online.)

**Option 3: Focusing on Convenience**

* **Description:** 線上輕鬆預訂，讓您享受便利無憂的行程規劃。 (Book easily online, allowing you to enjoy convenient and worry-free trip planning.)

**Option 4: Emphasizing a Wide Range**

* **Description:** 提供多樣化的線上訂票資訊，包括電影、演唱會、交通票券、主題樂園等 。(Providing a variety of online booking information, including movies, concerts, transportation tickets, theme parks, etc.)

**Option 5: For a Website Focusd on deals:**

* **Description:** 在線訂購獲得獨家優惠和折扣。 (Book online to get exclusive offers and discounts.)

**Which option to choose depends on the context of your website and the overall tone and message.** If you need to keep the description short, Option 1 is good. If you want to be a little more specific, Options 2, 3, or 4 are more suitable. Choose whichever best fits with your target audience and the services you offer. Also make sure to keep the description consistent with the overall style of your website.