Screenshot tools improve on the built-in Shift-Command-4 capture with annotation, scrolling capture, text recognition, pinned screenshots and quick sharing. If you take screenshots for documentation or bug reports every day, the time saved on cropping, marking up and uploading adds up.
CleanShot X is a popular paid all-in-one tool, and Shottr is a fast, lightweight app with scrolling capture and OCR. Flameshot is free and open source with in-place annotation, Skitch is a simple annotator, and Lightshot uploads captures for a shareable link. If screenshots may contain private data, check where cloud uploads are stored and who can access them.