Here’s a description for the WordPress post tag “平均年齡” (Píngjūn Niánlíng – Average Age) tailored for a Traditional Chinese audience:

**Description:** 有關文章涵蓋平均年齡相關內容，包括人口統計學上的平均年齡，不同群體或地區的平均年齡比較，以及影響平均年齡的因素，如醫療進步、生活水平等。此標籤旨在方便您查找有關年齡結構、壽命長短以及人口變化趨勢的文章。
**(Translation: Articles related to average age, including the average age in demography, comparisons of average ages across different groups or regions, and factors that influence average age, such as advances in medicine and living standards. This tag aims to help you find articles related to age structure, longevity, and trends in population changes.)**

**Why this description works:**

* **Clear and Concise:** It gets straight to the point, defining what the tag covers.
* **Specific:** It gives examples of the types of content that would be tagged, like demographic statistics, comparisons, and influencing factors.
* **Targeted Language:** It uses proper and formal Traditional Chinese.
* **User-Centric:** The description is written with the reader in mind, explaining the purpose of the tag and how it helps them find relevant information.
* **Keywords:** It naturally includes related keywords like “人口統計學” (demography), “壽命長短” (longevity), and “人口變化趨勢” (population change trends), which will enhance searchability.
* **Contextually Relevant:** It speaks to the broader implications of average age, suggesting the significance of this data.