Here are a few options for the WordPress post_tag description, along with some context for why they might be used:

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

> 當您鼻涕變黃時，可能代表身體正在對抗感染。 了解原因和可能的對策。
>
> (When your snot turns yellow, it may indicate your body is fighting an infection. Learn about the causes and possible countermeasures.)

* **Why it’s good:** Simple, clear, and informative. It directly addresses the title (“Nose Snot Turns Yellow”) and gives the user a basic understanding of the topic.

**Option 2 (Focus on Symptoms & Information):**

> 鼻涕變黃？ 這是鼻竇炎、感冒或其他疾病的徵兆嗎？ 立即了解鼻涕顏色變化的可能原因、伴隨的症狀，以及該如何緩解。
>
> (Yellow snot? Is this a sign of sinusitis, a cold, or another illness? Learn immediately the possible causes of changes in snot color, accompanying symptoms, and how to alleviate them.)

* **Why it’s good:** This focuses more on the broader issue and encourages engagement. It uses question words (“Is it…?”) to make the user curious and motivated to click the tag for more information.

**Option 3 (Focus on Keywords & Discovery):**

> 鼻涕, 鼻涕顏色, 黃鼻涕, 感冒, 鼻竇炎, 感染, 症状，治療
>
> (Snot, Snot color, Yellow snot, Cold, Sinusitis, Infection, Symptoms, Treatment)

* **Why it’s good:** This is a keyword-focused description. It doesn’t really read as a sentence, but is intended to help search engines and users find your content when searching for those terms. Useful as a search engine optimization (SEO) strategy, especially when the blog covers various related themes.

**Option 4 (Encouraging Reader to find more information)**
> 鼻涕變黃總是讓人擔心嗎？了解是什麼原因造成鼻涕變黃，以及什麼時候需要去看醫生。透過文章找到更多關於感冒或感染鼻涕的相關知識。
>
> (Is it always worrisome when your snot turns yellow? Learn what causes yellow snot and when you need to see a doctor. Find out more about colds or infections with yellow snot through this article.)

* **Why it’s good:** Addresses the user’s emotional reaction and indicates a call to action.
* **Important Note:** This option is better suited for specific blog tags or categories covering topics with potential health concerns to ease the reader’s worries.

**Choosing the Right Description:**

The best description for you depends on your specific blog’s focus and your SEO strategy. Consider these factors:

* **What’s the overall tone of your blog?** Formal, informal, informative, more playful?
* **Who is your target audience?** Are they health-conscious, concerned parents, etc.?
* **What do you want your user to do?** Learn more, seek information, get a clear understanding, find related articles?

Remember to tailor it to your context to maximize its effectiveness.