Here are a few options for a WordPress post tag description, depending on what you want to emphasize:

**Option 1: General & Concise (Suitable for most situations)**

> **標籤: ETF (Exchange Traded Fund)** – 追蹤特定指數、行業或商品的交易所交易基金 (Exchange Traded Fund)，方便投資者分散投資，降低風險。
>
> *Translation: **Tag: ETF (Exchange Traded Fund)** – Exchange Traded Funds (ETFs) that track specific indexes, industries, or commodities, providing investors with diversification and reduced risk.*

* **Highlights:** Clear, professional, and defines what an ETF *is*. Includes the English acronym for clarity.

**Option 2: Focus on the benefits for the investor**

> **標籤: ETF (交易所買賣基金)** – 了解ETF如何幫助您投資、分散風險，以及參與市場的多元化投資工具。 在此查看關於ETF的最新資訊、分析和投資策略。
>
> *Translation: **Tag: ETF (Exchange Traded Fund)** – Learn how ETFs can help you invest, diversify, and participate in the market with a flexible investment tool. Find the latest information, analysis, and investment strategies about ETFs here.*

* **Highlights:** Emphasizes the user benefit and includes a call to action/invitation to the content.

**Option 3: Simpler, suitable for a broader audience**

> **標籤: ETF (交易所買賣基金)** – 追蹤特定資產或指數的投資工具。 輕鬆接觸股票、債券、商品等的投資機會。
>
> *Translation: **Tag: ETF (Exchange Traded Fund)** – An investment tool that tracks specific assets or indexes. Easily access investment opportunities in stocks, bonds, commodities, etc.*

* **Highlights:** Uses more accessible language, assuming a lower level of financial literacy.

**Option 4: More detailed, if the site already has a good base of financial content**

> **標籤: ETF (交易所買賣基金)** – 包含股票型ETF, 債券型ETF, 商品型及其他ETF策略。 讓您深入了解不同ETF類型，如何選擇、投資，以及相關的稅務考量。 查閱有關ETF的投資新聞、市場分析，以及相關的投資建議。
>
> *Translation: **Tag: ETF (Exchange Traded Fund)** – Covering equity ETFs, bond ETFs, commodity ETFs, and other ETF strategies. Delve into different ETF types, how to choose and invest, and relevant tax considerations. Browse investment news, market analysis, and related investment advice about ETFs.*

* **Highlights:** Provides more specific information, suitable for a sophisticated audience and extensive ETF-related content.

**How to use the description in WordPress:**

1. **Log in to your WordPress admin panel.**
2. **Go to *Posts* > *Tags*.** (Or, depending on your theme, it might be under *Tags* or *Categories* under *Posts*).
3. **Find the “ETF” tag in Traditional Chinese.** (If you’re creating a new tag, fill in the information there).
4. **In the *Description* field, paste the description you chose above.**
5. **Click *Update* or *Save*.**

Choose the description that best fits the overall tone and scope of your website! Remember to use Traditional Chinese (Traditional Chinese will render properly on most WordPress setups, but to ensure it works, test it). I have assumed, for these descriptions, that the language setting of your WordPress blog is set to Traditional Chinese or Chinese (Taiwan).