<PackageReference Include="System.Data.SqlClient" Version="4.8.1" />

Microsoft.SqlServer.Server.SqlFacetAttribute

public class SqlFacetAttribute : Attribute
Annotates the returned result of a user-defined type (UDT) with additional information that can be used in Transact-SQL.
namespace Microsoft.SqlServer.Server { public class SqlFacetAttribute : Attribute { public bool IsFixedLength { get; set; } public bool IsNullable { get; set; } public int MaxSize { get; set; } public int Precision { get; set; } public int Scale { get; set; } public SqlFacetAttribute(); } }