For the Swiss Game Academy, I had to build a project to teach students some good practices to use in Unity. The first chapter of the course was focused on Attributes, ScriptableObjects, Enums and Inheritance.
This post talks about the Unity Attributes.

Example

When building tools or data-driven systems in Unity, the Inspector can quickly become cluttered. Luckily, Unity provides attributes like [Header], [Tooltip], [Range], and more to make your scripts much more user-friendly!

Here’s a quick example with a ScriptableObject Item:

[CreateAssetMenu(fileName = "New Item", menuName = "Alchemist's Inventory/Item")]
public class ItemData : ScriptableObject
{
    [Header("Core Item Information")]
    [Tooltip("The name of the item shown in the UI.")]
    public string itemName;

    [Tooltip("The description of the item.")]
    [TextArea(3, 5)]
    public string description;

    [Tooltip("The monetary value of the item.")]
    [Range(0, 999)]
    public int value;

    [Space(15)]
    [Header("Item Graphical Settings")]
    [Tooltip("The icon that represents this item.")]
    public Sprite icon;

    [Tooltip("The prefab spawned in the world.")]
    public GameObject prefab;

    [Tooltip("Trail colors when the object is spawned.")]
    [ColorUsage(true, true)]
    public Color[] trailColors = new Color[2];
}

Result

Here are the results:

Before using attributes	After using attributes

In this case fields are still readable but this is a simple item. On much larger ones, the result might be much more confusing.

Conclusion

That is why we use Attributes like:

• [Header("The name of the header")] To creates categories in the Inspector for readability
• [Tooltip] To add hover descriptions (great for designers on your team)
• [Space] to add visual separation between sections.
• [Range] to add a slider, preventing invalid values
• [TextArea] to let you write multi-line text fields
• [ColorUsage] to enable HDR colors for vibrant effects

These tiny attributes may look simple, but they dramatically improve workflow and collaboration, especially when working with non-programmers.
There are multiple other attributes that can be useful and a github page lists some of the most useful ones HERE