HMRC are likely to assess any provider that actively markets in the contracting market and offers a limited company solution as a MSCP.
The term is no more than a label used to indicate that the provider is a specialist provider of services to the contracting market. As a specialist provider HMRC expect a greater level of understanding and appreciation of all the rules applying to the market. As a result it can be argued that in many respects a compliant MSCP is likely to deliver a significantly more professional and rounded solution to contractors; as they understand all the issues.
The only time a MSCP represents a risk to an agency is where that provider is operating procedures that would be seen as not compliant by HMRC. This is defined within the MSC legislation as involved.