Here are a few options for the WordPress post_tag description, in Traditional Chinese, considering different aspects:

**Option 1: Concise and Informative (Focus on Functionality)**

* **Description:** 輕鬆掃描，快速登機。電子登機證讓您的旅行更加便捷。 (Simplified: 轻松扫描，快速登机。电子登机证让您的旅行更加便捷。)
* **Translation:** Scan easily, board quickly. Electronic boarding passes make your travel more convenient.
* **Why it works:** Directly highlights the core benefit – ease and speed.

**Option 2: Focus on Technology & Modernity**

* **Description:** 數位時代的登機體驗，省時省力，告別傳統紙本。立刻下載您的電子登機證，展開旅程。（简体：數位时代的登机体验，省时省力，告别传统纸本。立刻下载您的电子登机证，展开旅程。）
* **Translation:** Boarding experience in the digital age, saves time and effort, goodbye to traditional paper. Download your electronic boarding pass now, and start your journey.
* **Why it works:** Appeals to tech-savviness and the desire for a modern experience.

**Option 3: Problem/Solution Focused**

* **Description:** 免受排隊之苦，減少行李遺失風險。使用電子登機證，享受更順暢的登機流程。(Simplified: 免受排队之苦，减少行李遗失风险。使用电子登机证，享受更顺畅的登机流程。)
* **Translation:** Avoid the suffering of queuing, reduce the risk of lost luggage. Use electronic boarding pass, enjoy a smoother boarding process.
* **Why it works:** Addresses common travel pain points and presents the electronic boarding pass as a solution.

**Option 4: Focus on Environment & Convenience**

* **Description:** 節省紙張，綠色環保。電子登機證，方便攜帶，隨時查看。 (Simplified: 节省纸张，绿色环保。电子登机证，方便携带，随时查看。)
* **Translation:** Save paper, green and environmentally friendly. Electronic boarding pass, easy to carry, view anytime.
* **Why it works:** Appeals to environmentally conscious travelers and highlights convenience.

**How to Decide:**

Choose the description that best aligns with the overall tone and content of your blog. If your blog is about travel efficiency, options 1 & 2 would be good. If you focus more on the environmental aspects, option 4 would be a good fit.

**Important:**

* Make sure the description is concise and easily understood.
* Use clear and grammatically correct Traditional Chinese.
* Consider your target audience and their preferences.
* Keep it relevant to the “電子登機證” topic.

I recommend one of the options above, depending on your overall blog’s topic and style. For instance, Option 1 or 2 are good suggestions. For the best result, tailor the prompt to your website’s theme.