It may get picked up by bots (bots crawl the text on your site looking for things to index – google, yahoo, bing, etc)
Which would mean it might get indexed and show up in google searches.
You will probably find a million different opinions on what should, and should not go in to robots.txt.
I have 1 site where I disallow a bunch of stuff, and another where I don’t block anything. Both sites get indexed fine. You can do a Google search for ‘wordpress robots.txt’ to read various tutorials/opinions and make up your own mind what is best.
Just remember, in robots.txt, you don’t allow anything.
To block something from showing up in a search, you would put Disallow: whatever in there…. but the command Allow: whatever doesn’t exist. So to allow something…. you just don’t disallow it, make sense?