You should add a generator tag to your Eleventy site

<meta name="generator" content="{{ eleventy.generator }}">
How to add a generator meta tag to your Eleventy site in nunjucks, available in Eleventy v1.0.1

This single line of code, added to your Eleventy site (in the <head>), can:

I think you should add it if you're using Eleventy. I just did. I mean… or not… it's up to you. I guess it's pretty cool you can even pick.

Eleventy Supplied Data
A docs page for Eleventy v1.0.1, a simpler static site generator.
Official documentation on the eleventy data object and generator key

Update

Zach Leatherman goes into further detail in a short Eleventy YouTube video: