Weasel words damage trust. And weasels are worth avoiding.
There are two traps to look out for:
Promotional weasel words. Every experienced marketing copywriter knows how to use them. "As much as half off," means, "There is at least one item on sale for half of some price of dubious origin. Everything else is any price we want it to be."
When you say, "nearly 500," it's a totally different message than, "500."
Words like, "renowned," "fabled," and "deluxe" are weasely. They let you wriggle out of your promise.
Resumes are a natural habitat for weasel words, fyi.
You can ban the weasel words if you like. It takes a leap of courage, and then things get easier.
The other kind:
When you try to enter into an agreement with a weasel, you'll need to over-lawyer and over-document every element of your interaction, because he'll be working overtime to rewrite, redefine and generally squirm out of what he said, what he promised and what you expect.
If you can, don't work with weasels.
First step: don't be one.