entity rules -- error message for validation

I have created a new entity of type date and I have given the rule where date is grater than today but if user enters the date which is less than the current date I need to show a message How can achieve that

Hello Shiva,

Welcome to Kore.ai Community
Please refer to the below documentation for more information on using entity.

Thank you,
Srujan Madderla
Kore.ai Community Team