Here are a few options for a WordPress post_tag description, in Traditional Chinese, for the title “排球技巧”, varying in length and focus:

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

> 學習排球的各種技巧，提升你的球技！
>
> *(Learn various volleyball skills and improve your game!)*

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

> 深入探索排球技巧，包含發球、接球、扣球、攔網等關鍵要素，助你掌握比賽精髓。
>
> *(Dive deep into volleyball skills, including key elements like serving, receiving, spiking, and blocking, to help you master the essence of the game.)*

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

> 想成為更棒的排球選手嗎？在這裡你可以找到提升技巧的秘訣，從基礎訓練到進階戰術，讓你不斷進步！
>
> *(Want to become a better volleyball player? Here you can find the secrets to improving your skills, from basic training to advanced tactics, to help you progress constantly!)*

**Option 4 (Emphasis on Learning Resource):**

> 本分類彙集了排球技巧相關的文章、影片和教學資源，讓你輕鬆學習和掌握排球的各種技巧。
>
> *(This category collects articles, videos, and educational resources related to volleyball skills, making it easy for you to learn and master all kinds of volleyball techniques.)*

**Choosing the Best Option:**

* **Consider the audience:** Are you writing for beginners, intermediate players, or experts? Tailor the description’s language and complexity accordingly.
* **Consider the content of your posts:** Do your posts focus more on the basics or on advanced strategies? The description should reflect the type of content tagged with “排球技巧.”
* **Length limits:** WordPress themes may limit the length of tag descriptions.

I would suggest Option 2 or 3 as being good starting points, then adjust based on the specifics of your website. Remember to keep it descriptive and informative while still being concise.