The "Program Name" column in MySQL Workbench comes from a program_name connection attribute. The MySQL documentation incorrectly claims that:
MySQL Connector/NET defines these attributes:
_program_name: The client name
This is wrong in two ways: the attribute name has a typo (leading underscore) and the code that sets it was deleted.
There is no way (a connection string setting or otherwise) to set the value of this attribute in MySQL Connector/NET. Furthermore, the connection attributes are part of the initial handshake so there is no way to set them after the connection is established (e.g., in your application code).
If you're willing to change ADO.NET connector libraries, the MySqlConnector library added support for an Application Name connection string option in v0.44.0; this will let you control the connection attribute that's sent to the server (and it will show up in MySQL Workbench).
