There are socially sensitive nerds, but "pleasant" usually describes their SELF-image, not the view that others have of them.

Usually nerds like you describe are socially anxious and attempt to "take care" of everyone around them by conforming to their expectations and desires. Normal people actually find it exhausting to hang out with socially anxious "nice guy" nerds.

Also, almost all "nice guys" have a lot of repressed anger and rage from trauma in the past. The "nice guys" have repressed it and so are not aware of it, but others see the anger, usually manifesting as cynicism, sarcasm, or passivity.

Anyway true pleasant, sensitive people are rarely also described as nerds. They'd be described as socially comfortable, pleasant, emotionally sensitive, and intelligent.

"Nerd" would not enter the description unless there is some amount of social anxiety, awkwardness, or intense need for external validation.