How precise is CEO enrichment? (Emails and contacts scraper)

Hey, just a few questions:

I am enriching my leads via ‘emails and contacts scraper’ to get the decision makers (CEO’s, managers etc) from my lead list.

I was wondering:

  1. How precise is it? Is it correct 100% of the time or is there sometimes problems / the scraper finds the wrong contact
  2. How does it work if the CEO’s email / name is not on the website nor the LinkedIn?

Any response would be appreciated