Rui CarmoShottr is a lightweight macOS screenshot and annotation tool that manages to stay focused on the useful bits while still packing in a surprising number of editing features: quick capture, measurement, redaction, OCR, scrolling screenshots, pinning, pixelation, arrows, callouts and the usual visual markup without turning into a full design app. It has the right kind of small-tool energy, and is one of those utilities that is easy to justify keeping around all the time.
It also has a free trial mode and is available via Homebrew, which makes it particularly easy to install and keep up to date:
brew install --cask shottr