画蛇添足

Literal meaning

draw a snake and add feet

Story

In the old story, someone finished drawing a snake first, then added feet to show off. Because snakes do not have feet, the extra detail made the drawing wrong.

Modern usage

Use it when someone overdoes a solution, adds unnecessary features, or complicates a clean plan.

Example

这zhè 个ge 页yè 面miàn 已yǐ 经jīng 很hěn 清qīng 楚chǔ 了le, ，zài 再jiā 加shí 十ge 个àn 按niǔ 钮jiù 就shì 是huà 画shé 蛇tiān 添zú. 足 。 ▶ This page is already clear. Adding ten more buttons would be overdoing it.