for example the subject field on an event should only be 25 characters long.

You should be able to limit this in the salesforce field settings. I believe you can olso opt to override the meta data settings by clicking on the field in the model editor (not in a layout) and then define max chatacters for text fields

Hi Jaime,

Raymond is correct. Here’s how to do it in the metadata settings of a specific field, although I would say that it’s generally best practice to change this on the Salesforce side first.

Sincerely,

Karl