A sharp chisel is safer than a dull one. Same with ideas: the vague ones are the ones that slip.

A dull blade requires force, and force is what makes a tool jump out of the cut. Sharpness means the chisel goes where you put it, which is why the sharper tool is the less dangerous one. A vague idea behaves the same way: you have to push it, it wanders, and the project ends up somewhere you did not intend.

Write your current idea in one sentence with no hedging words in it. If you cannot, the vagueness is still in the idea rather than in your writing. Sharpen it until the sentence is specific enough to rule things out.