wsdl - Web service that has Edmx objects as parameters -

i feel exposing edmx class parameter web service not idea. feel it's wrong design. eg.

[webmethod] mywebservice(int customerid, userprofile profile){ } 

now userprofile class generated edmx framework. might argue if profile object input not proper id (edmx id) because created out of context (since web service can called external consumer).

but i'm looking more explanation why exposing edmx class web service not design. if think it's ok, please tell me.

thanks

it's considered design practice keep data contracts of web service , data model objects associated database separate, if required change entity model used @ of web service, without having change interface expose consumers of service.