Is it good to have a manager that is generally positive or generally negative? Do you really think your manager's outlook can affect your performance? What about the 'tough' manager versus a manager who gives more positive ratings?
Is it possible that an ‘awesome’ employee from company A could become a mediocre or poor employee at company B because of the number of positive/negative comments made by their manager?
An article from the Harvard Business Review explores this and it turns out that yes, managers who give more positive ratings end up having employees who perform better.
Anyone who joined us in the discussions with the subordinates of these two sets of managers would have instantly seen the impact. The people who’d received more positive ratings felt lifted up and supported. And that vote of confidence made them more optimistic about future improvement. Conversely, subordinates rated by the consistently tougher managers were confused or discouraged—often both. They felt they were not valued or trusted, and that it was impossible to succeed. - HBR
So as you write evaluations for your employees, be honest but also remember to put in plenty of positive comments for your direct reports.
They’re going to be better at their job because of it.