EntityDefinition
A custom object Name must be in english and PascalCase
Field: QualifiedApiName
Regex: ^[A-Z][A-Za-z0-9]*(__c|__mdt|__ka|__kav)$
Example
InsurancePolicy
A custom object Description is required
Field: Description
Regex: ^.{20,}$
Example
More than 20 chars
Less than 100 custom fields
Field: Fields.totalSize
Maximum one custom trigger per object
Field: ApexTriggers.totalSize
Maximum 15 record types per object
Field: RecordTypes.totalSize