DataSource Controls :: Validating Length Of Data In Context With Stored Procedure Parameters?

I am building a WCF Web Service that has a Business Logic layer (that implements all validation logic and other business rules) and a Data Access Layer that makes calls to Stored Procedures in my database.

I would like to be able to validate the length of data passed against that of the length of the parameters in the Stored Procedures without having to explicitly define the parameter lengths in my WCF Web Service.

Eg:

Person Object
Person.Name = "John Dhoe"
Person.Age = 37
SQL Stored Procedure
SavePerson
FullName Varchar(15)
Age Int

In my BLL or DAL, I would like to be able to do something like :

If(Person.Name.length == SavePerson.Parameters["FullName"].Length)
{
Return true;
}
else
{
Return false;
}

Has anyone tried this out before? Is this even possible?