Unity sample MonoBehaviour explaining how to associate simple strings with enums.

EnumDescription.cs

using System;
using System.ComponentModel;
using UnityEngine;

public class EnumDescription : MonoBehaviour
{
    public enum PlayerState
    {
        Unknown,
        [Description("Alive and kicking")]
        Alive,
        [Description("Dead as a duck")]
        Dead
    }

    // Start is called before the first frame update
    void Start()
    {
        var state = PlayerState.Dead;
        Debug.Log("Player is " + state.GetDescription());
    }
}

public static class EnumExtensions
{
    public static string GetDescription(this Enum value)
    {
        var type = value.GetType();
        var name = Enum.GetName(type, value);
        if (name != null)
        {
            var field = type.GetField(name);
            if (field != null)
            {
                if (Attribute.GetCustomAttribute(field,
                  typeof(DescriptionAttribute)) is DescriptionAttribute attr)
                    return attr.Description;
            }
        }
        return name;
    }
}