Here are a few description options for the WordPress post tag “自然數” (Natural Numbers) in Traditional Chinese, varying in conciseness and focus:

**Option 1: Concise & Direct (Most Common Use)**

> 「自然數」標籤，用於標記與正整數相關的內容。

*Translation: “The ‘Natural Numbers’ tag used to mark content related to positive integers.”*

**Option 2: Beginner-Friendly**

> 關於自然數的資訊，也就是我們從小學就開始學習的數字，例如：1, 2, 3, 4等等。

*Translation: “Information about natural numbers, which are the numbers we start learning in elementary school, like: 1, 2, 3, 4, etc.”*

**Option 3: Scholarly/Technical (Depending on Content)**

> 標記涉及自然數 (ℕ) 以及其各種性質、運算和在數學中的應用的文章。

*Translation: “Marks articles related to natural numbers (ℕ) and their various properties, operations, and applications in mathematics.”*

**Option 4: Broader, suitable when the site covers many concepts**

> 與自然數相關的內容，包含定義、性質、應用。

*Translation: “Content related to natural numbers, including definitions, properties, and applications.”*

**How to choose:**

* **Overall site focus:** If the site is for beginners, option 2 might be best. If its more academic, option 3 is better.
* **Target audience:** Consider who typically reads your blog.
* **The tag’s usage:** What kind of content will this tag be applied to? The description should reflect that.
* **Length constraints:** WordPress allows a moderate length, but shorter is usually easier to read.
* **SEO friendly:** This description is in Traditional Chinese, and the keyword “自然數” is included.

Remember to always save your tag description in the WordPress admin area after adding the tag. I recommend Option 1 or Option 4, unless the site requires more explanation.