In Eligibility assessment, they will do all sorts of verfications against all your reference / employment letters. Once he feels everything good then Agent will re-assess / recalculate your CRS score to see if you are still above or equal to the cut-off with which you invited your PR. They also verify your POF, travel history, personal history, passports validity, Spouse documents etc. Long story short , this is one of th critical stage in our PR process. In the end, agent will provide his recommendation to Visa Officer.
Hope it helps.