Rust makes your tool weak and encourages the spread of plant diseases. The oxidation process corrodes metal and makes it ineffective.
The best way to prevent rust is by storing your hand tools in a cool, dry place. Keeping them away from water eliminates the chances of rust formation.
White vinegar has a mild acidity level, which makes it great for rust remove. It peels off the oxide coating from your aluminum hand tool, leaving its surfaces sleek and shiny.
When rust forms on a tool, it becomes hard to use it. Thus, WD-40 is a popular lubricant that allows parts in a tool to move swiftly.
The short answer is: go for it. WD40 is a decent quick thing to use. It might not extend the life of your tools indefinitely but will add years to their life.– Source