Here are a few options for the WordPress `post_tag` description, along with explanations, focusing on clarity and usefulness:

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

> 學習寫作說明文的技巧和方法。包含文章結構、用字遣詞和避免常見錯誤等實用指南。

* **Explanation:** This is a straightforward and informative description. It immediately states the topic and hints at the content (techniques, methods, structure, language, and common mistakes).

**Option 2 (Focus on Benefits):**

> 想讓你的說明文更清晰、更易懂？ 這裡提供寫作說明文的秘訣，幫助你清楚地傳達資訊，有效地說明事物，並讓讀者更容易理解。

* **Explanation:** This option focuses on the benefits the reader will get. It uses a question to engage the reader and emphasizes the positive outcomes of learning how to write good explanatory texts. This is a good choice for SEO purposes.

**Option 3 (More Specific, Uses Keywords):**

> 涵蓋說明文寫作的各個方面，包括文章結構、段落組織、開頭與結尾、用字遣詞、修辭手法及範例分析，讓你掌握寫好說明文的實用技巧，寫出清晰、有條理、引人入勝的說明文。

* **Explanation:** This is a more detailed description, using key terms relevant to explaining how to write explanation texts (e.g., article structure, paragraph organization, opening/closing, language, use of rhetoric, example analysis). This helps in SEO by including relevant keywords.

**Option 4 (For Beginners):**

> 從零開始學習寫作好的說明文！ 這裡有寫作說明文的基本知識，幫助你建立扎實的基礎，逐步掌握清楚且有條理地解釋事物的方法。

* **Explanation:** This targets beginners and emphasises on a gentle approach of reading from scratch.

**Choosing the best description:**

* **Consider your audience:** Who are you writing for? Knowledgeable writers or beginners?
* **SEO:** Include relevant keywords (e.g., “說明文”, “寫作技巧”, “文章結構” – Explanation Text, writing techniques, article structure).
* **Brevity:** WordPress tag descriptions should be concise and to the point.

I recommend using **Option 3** or **Option 2** because they provide a good balance between information, benefits, and keyword inclusion while being clear and concise. Remember to tailor the description to best suit the actual content of your blog post!