How do you pre-qualify your Lead before contact?

I am trying to understand if there is an actual pain behind that: Do you spend a lot of time manually qualifying each lead?

I ask that because I’m testing a small Lead scoring app for marketing agencies and outbound teams.

Mainly looking for honest feedback:

Would a tool like this actually save you time before outreach?
Would you trust this type of scoring?
What would make the output useful enough to pay for?