Here are a few description options for the WordPress post tag “罰息” in Traditional Chinese, varying in style and context:

**Option 1: Short and Direct (Good for general use)**

* **繁體中文:** 懲罰性利息與額外費用。
* **Translation:** Penal interest and additional fees.

**Option 2: More Detailed (If the context is about loans and interest)**

* **繁體中文:** 貸款未按時還款或違反合約條款時，銀行或金融機構收取的額外利息。
* **Translation:** Extra interest charged by banks or financial institutions when a loan is not repaid on time or contract terms are violated.

**Option 3: Emphasizes Understanding (Suitable for educational content)**

* **繁體中文:** 罰息：了解延遲付款或違反貸款協議所產生的利息費用。
* **Translation:** Penal Interest: Understanding the interest charges arising from late payments or breach of loan agreements.

**Option 4: Focus on Consequences (For a more somber tone or related to financial advice)**

* **繁體中文:** 未能遵守還款義務的財務後果。包括逾期付款的罰息費用。
* **Translation:** The financial consequences of failing to fulfill repayment obligations, including penal interest charges for overdue payments.

**To choose the best one, consider:**

* **The Audience:** Who are you writing for? Are they financial experts, or is this for the general public?
* **The Context:** What is the main topic of the posts using this tag? Is it about personal finance, loans, or something else?
* **SEO:** Use keywords that people actually search for. “罰息” itself is a good start, but consider adding related terms like “逾期付款” (late payment), “貸款” (loan), or “利息” (interest).

I recommend choosing Option 1 or 2 for most general purposes. Good luck with your WordPress post!