Keep in mind that these tools that talk about this are somewhat limited. And that Google has no idea what you are targeting for keywords – it’s going to look at the content and decide what it’s about and then rank it for that. The tools just help (in a very limited way) give you some best practice concepts to help ensure that what Google sees the page being about is the same as what you’re thinking the page is about.
fAs such… a page about “Widgets” that only uses the word “Widgets” in the title and meta description (which doesn’t even appear on the page) probably isn’t really about widgets. So your tool is just saying, “Hey, are you sure this is really about widgets? You’re not really talking about them very much, here.”