蛇足

1. Origins, structure, and basic meaning

• Structure: 蛇足 (だそく) literally combines snake 蛇 and foot 足, denoting an unnecessary addition to something already complete.
• Basic usage: It describes an extra explanation or remark that adds no value and may weaken the whole.

2. Common pitfalls and similar expressions

• An addition that is specifically superfluous
  • 蛇足かもしれない politely warns that the following remark may be unnecessary, not merely that it comes last.