straight-from-the-shoulder

adjective

Manifesting honesty and directness, especially in speech: candid, direct, downright, forthright, frank, honest, ingenuous, man-to-man, open, plainspoken, straight, straightforward, straight-out, unreserved. Informal straight-shooting. See clear/unclear, show/hide.

In a direct, forthright manner, as in I'll tell you, straight from the shoulder, that you'll have to do better or they'll fire you. This expression comes from boxing, where it describes a blow delivered with full force. Its figurative use dates from the late 1800s.