Holt Tools is an addon that adds a utility panel to the 3D viewport's N-menu, providing a collection of workflow operations. The toolset includes functions for cleaning up blend files and selecting objects based on specific criteria like name, object type, or vertex count.

The addon also features lighting controls for adjusting power and color values, randomizing colors, and applying changes to either selected lights or the entire scene. Additionally, it offers quick mesh decimation for optimization, a fast interface theme switcher, and a toggle for world volumes to preview atmospheric effects without modifying world shader nodes.