Here are a few options for a WordPress post_tag description, with varying levels of detail and focus, all in Traditional Chinese and for the title “地震大小” (earthquake size/magnitude):

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

> 用於標記文章，討論地震的震級、規模與影響大小。 涵蓋裡氏地震規模、矩震級等不同衡量標準。

* **Translation:** Used to tag articles discussing the magnitude, scale, and impact size of earthquakes. Covers different measurement standards like the Richter Scale and Moment Magnitude Scale.

**Option 2 (More Explanation):**

> 標示與地震大小相關的文章。這包含了各種衡量地震強度的指標，如震級、震源深度，以及地震造成的破壞程度。 我們會探討地震大小的不同量測方式，例如裡氏規模、矩震級等。 了解地震大小能幫助我們評估潛在的風險，並做好應對措施。

* **Translation:** Tags articles related to the size of earthquakes. This includes various metrics for measuring earthquake intensity, such as magnitude, focal depth, and the degree of destruction caused by the earthquake. We will explore different ways of measuring earthquake size, such as the Richter Scale and Moment Magnitude Scale. Understanding earthquake size can help us assess potential risks and prepare for response measures.

**Option 3 (Focus on Practical Application):**

> 標籤用於分類與地震大小相關的資訊。從震級測量到地震造成的影响，此標籤涵蓋了解地震規模如何影響我們的日常。 包括如何衡量地震强度、以及如何評估地震可能带来的风险。 了解地震大小的重要性，有助於我們做好防災準備，減少災害損失。

* **Translation:** This tag categorizes information related to earthquake size. From magnitude measurements to the impact caused by earthquakes, this tag covers how understanding earthquake size affects our daily lives. It includes how to measure earthquake intensity and how to assess the potential risks they pose. Understanding the importance of earthquake size helps us prepare for disaster prevention and reduce disaster losses.

**Option 4 (Short & Sweet):**

> 關於地震規模的討論。包括震級、大小及影響。

* **Translation:** Discussions concerning earthquake magnitude. Including magnitude, size and impact.

**Which one you choose depends on your website and your target audience:**

* **Option 1** is a good all-rounder, direct and descriptive.
* **Option 2** is more detailed and educational.
* **Option 3** emphasizes the practical aspects and disaster preparedness.
* **Option 4** is the shortest and most concise.

Remember to choose the description that best fits your website’s focus and the type of content you are tagging. You can also adapt and combine elements from these options to create the perfect description for your needs.