Rule prototype pattern for validation

RulePrototype.cs

var phone = "+77771112233"
var record = GetRecordById(Id);

new RulePrototypeConcrete()
                        .With(new ChangePhoneRule(phone))
                        .With(new DeletePhoneRule(phone))
                        .With(new ExistsPhoneRule(phone))
                        .Execute(record);

public abstract class RulePrototype : IDisposable
    {
        protected List<Rule> rules = new List<Rule>();

        public abstract RulePrototype With(Rule rule);

        public abstract AgentResult Execute(CardSMSApplication cardApp);

        public void Dispose()
        {
            rules.Clear();
        }
    }
    public abstract class Rule
    {
        protected bool isResult = false;
        protected AgentResult result = new AgentResult();
        public abstract bool IsExecute { get; protected set; }
        internal abstract AgentResult GetResult(TestApplication app);
    }
    public class RulePrototypeConcrete : RulePrototype
    {
        public override RulePrototype With(Rule rule)
        {
            rules.Add(rule);
            return this;
        }

        public override AgentResult Execute(TestApplication app)
        {
            AgentResult result = new AgentResult();

            foreach(Rule r in rules)
            {
                result = r.GetResult(app);

                if(r.IsExecute)
                    break;
            }
            return result;
        }
    }
    
    public class ChangePhoneRule : Rule
    {
        string _phone;
        public ChangePhoneRule(string phone)
        {
            _phone = phone;
        }
        public override bool IsExecute
        {
            get
            {
                return isResult;
            }
            protected set
            {
                isResult = value;
            }
        }

        internal override AgentResult GetResult(TestApplication app)
        {
            if(app.ReasonType == AppType.CHNG && app.NewPhone == _phone)
            {
                ...... DO Somting ......
                IsExecute = true;
                result = FailValidation.GetError("ERROR");
            }
            return result;
        }
    }
    
    public class DeletePhoneRule : Rule
    {
        string _phone;
        public ChangePhoneRule(string phone)
        {
            _phone = phone;
        }
        public override bool IsExecute
        {
            get
            {
                return isResult;
            }
            protected set
            {
                isResult = value;
            }
        }

        internal override AgentResult GetResult(TestApplication app)
        {
            if(app.ReasonType == AppType.CHNG && app.NewPhone == _phone)
            {
                ...... DO Somting ......
                IsExecute = true;
                result = FailValidation.GetError("ERROR");
            }
            return result;
        }
    }
    
    public class ExistsPhoneRule : Rule
    {
        string _phone;
        public ChangePhoneRule(string phone)
        {
            _phone = phone;
        }
        public override bool IsExecute
        {
            get
            {
                return isResult;
            }
            protected set
            {
                isResult = value;
            }
        }

        internal override AgentResult GetResult(TestApplication app)
        {
            if(app.ReasonType == AppType.CHNG && app.NewPhone == _phone)
            {
                ...... DO Somting ......
                IsExecute = true;
                result = FailValidation.GetError("ERROR");
            }
            return result;
        }
    }