Multiple answers are selected.
Profit % + D/D % + Providers balance + Months of successful tradings.
These are most important to justify a signal.
Already I had posted a blog here regarding copy trades, hope my logic will be helpful to find out a good signal.
Find out better signal
Careful from fraud signal
profit%+Drawdown %+acco. age
The most important factor you didn't include in list which is equity , mostly signal accounts DD have a direct connection with equity. Holding an equity is a basic Art or technique and it shows how much correct predictions or strategy.
Mostly peoples works with small capital and other side mostly brokers also don't likes if trader put big amount they knows trader will win. Why peoples don't put big amount many factors they don't trust on broker, they afraid that they will loose the game etc.
So if a limited capital is involve then an equity is everything.
Best of luck