Weights need a reason.
A weighted score is only as useful as the assumptions behind it.
Make importance explicit
Weights express relative importance inside one evaluation. A weight of five contributes five times as much as a weight of one. Explain why that difference makes sense for the work instead of using precision to disguise uncertainty.
Use a consistent scale
Scores run from one to five; zero means unscored. Agree what a high or low score means before entering ratings. Avoid comparing results across evaluations that use different criteria or interpretations as though they were an objective market ranking.
Read the arithmetic correctly
The weighted result is the sum of weight multiplied by score divided by the sum of weights. For weights three and two with scores four and three, the result is 3.6 out of five. This is deterministic arithmetic over entered judgments.
Write the limitations
The number does not contain every trade-off. Record assumptions, evidence gaps, or constraints alongside the recommendation. Revisit the evaluation when criteria or scores change.