Here are a few options for a WordPress post_tag description for “21天法則” in Traditional Chinese, ranging in style and detail:

**Option 1 (Concise & Direct):**

* **Title:** 21天法則
* **Description:** 探索「21天法則」的奧秘！了解如何透過持續的努力，養成新習慣，達到目標。 探討如何透過21天的堅持，建立並鞏固你的目標與好習慣。

**Option 2 (Slightly More Descriptive):**

* **Title:** 21天法則
* **Description:** 深入解析「21天法則」，這是一個幫助你建立新習慣、打破舊習的實用方法。 學習如何運用21天持續性的努力，在工作、生活、健康等方面得到改善。

**Option 3 (Focus on Benefits):**

* **Title:** 21天法則
* **Description:** 想改變？ 从「21天法則」開始！ 掌握這個簡單有效的策略，讓你在21天內養成好習慣、實現個人成長。 透過持續的努力和紀律，建立更健康、更有效率的生活方式。

**Option 4 (Informal & Engaging):**

* **Title:** 21天法則
* **Description:** 21天法則是什麼？ 一起來了解這個超棒的技巧，輕鬆養成習慣、擺脫壞習慣！ 找到實現目標的秘訣，讓你的生活更上一層樓！

**Explanation of Choices:**

* **Clarity:** All descriptions clearly state what the tag is about.
* **Keywords:** They subtly incorporate relevant keywords like “習慣” (habits), “目標” (goals), “改變” (change), “持續” (persistence), etc. These can help with internal linking and SEO.
* **Call to Action (Implicit):** They encourage readers to explore content related to this tag.
* **Brevity:** WordPress tag descriptions shouldn’t be overly long. These are generally appropriate in length.
* **Tone:** The options vary in tone, allowing you to choose the one that best suits the overall style of your blog.
* **Vocabulary:** Using common and accessible Traditional Chinese terms.

**Which Option to Choose:**

Choose the description that best fits your blog’s tone and the type of content that will be tagged with “21天法則.” Consider the target audience and the purpose of your content. If you are a more technical blog, options 1 and 2 might be better. If you enjoy an informal tone, go with numbers 3 or 4.

**Pro Tip:** Within your WordPress settings, you could also add a longer “Description” to the tag itself, which could better explain the subject in detail. The option above is a shorter version for displaying the tag’s description.