There is not single tool that does it.

Depends on your budget and the level of effort you want to do.

You can use ahrefs.com to get a pretty good idea of the competition strength of the top few sites for your chosen keyword/s.

If you want to crunch a lot of keywords, then I'd suggest SECockpit (but I'm obviously biased)

Long tail platinum can give you a quick measure of how competitive a keyword is with it's AVC (Average Keyword Competitiveness) metric. it's one of the best keyword tools you can purchase today.

You can also find out the level of competition for a keyword manually by analysing the top 10 ranking sites in Google to know how much effort they are putting into ranking for that keyword. The more effort they are putting, the higher the competition or the more optimised their sites are for your target keyword, the higher the competition.