Model DataAnnotation test

Model:
public class OrganisationVM
{
    public int Id { get; set; }

    [Required]
    [MinLength(5, ErrorMessage = "Must be at least 5 characters long")]

    public string Name { get; set; }
    [Required]
    [Range(1, 100000, ErrorMessage = "Must be greater than 1 and less than 1000000")]
    public int Employees { get; set; }
}

XUnitTest:

public class OrganisationVMTest
{
    [Fact]
    public void OrganisationVMValid()
    {
        // Arrange
        var model = new OrganisationVM
        {
            Id = 1,
            Name = "Julian",
            Employees = 1000
        };
        var context = new ValidationContext(model, null, null);
        var result = new List<ValidationResult>();

        // Act
        var valid = Validator.TryValidateObject(model, context, result, true);

        Assert.True(valid);
    }

    [Fact]
    public void OrganisationVM_name_required()
    {
        // Arrange
        var model = new OrganisationVM
        {
            Id = 1,
            Employees = 1000
        };
        var context = new ValidationContext(model, null, null);
        var result = new List<ValidationResult>();

        // Act
        var valid = Validator.TryValidateObject(model, context, result, true);

        Assert.False(valid);
        var failure = Assert.Single(
            result,
            x => x.ErrorMessage == "The Name field is required.");
        Assert.Single(failure.MemberNames, x => x == "Name");
    }

    [Fact]
    public void OrganisationVM_Name_Short()
    {
        // Arrange
        var model = new OrganisationVM
        {
            Id = 1,
            Name = "July",
            Employees = 1000
        };

        var context = new ValidationContext(model, null, null);
        var result = new List<ValidationResult>();

        // Act
        var valid = Validator.TryValidateObject(model, context, result, true);

        Assert.False(valid);
        var failure = Assert.Single(
            result,
            x => x.ErrorMessage == "Must be at least 5 characters long");
        Assert.Single(failure.MemberNames, x => x == "Name");
    }

    [Fact]
    public void OrganisationVM_Employee_Range()
    {
        // Arrange
        var model = new OrganisationVM
        {
            Id = 1,
            Name = "Julian",
            Employees = 0
        };
        var context = new ValidationContext(model, null, null);
        var result = new List<ValidationResult>();

        // Act
        var valid = Validator.TryValidateObject(model, context, result, true);

        Assert.False(valid);
        var failure = Assert.Single(
            result,
            x => x.ErrorMessage == "Must be greater than 1 and less than 1000000");
        Assert.Single(failure.MemberNames, x => x == "Employees");
    }

    [Fact]
    public void OrganisationVM_Employee_Required()
    {
        // Arrange
        var model = new OrganisationVM
        {
            Id = 1,
            Name = "Julian"
        };
        var context = new ValidationContext(model, null, null);
        var result = new List<ValidationResult>();

        // Act
        var valid = Validator.TryValidateObject(model, context, result, true);

        Assert.False(valid);
    }
}