What is the purpose of payment (payment description) used when withdrawing funds to a bank via SWIFT transfer?

When withdrawing funds via SWIFT bankwire transfer, one of the following payment purposes is indicated:

For USD or EUR currency: TRANSFER UNDER AGENT AGREEMENT ХХХХХХХ. UNUSED FUNDS, NON COMMERCIAL TRANSFER, where XXXXXXX is the agreement number corresponding to your trading account number.

For KZT currency: TRANSFER UNDER AGENT AG (ХХХХХХХ) (DATE) UNUSED FUNDS, NON COMMERCIAL TRANSFER, where XXXXXXX is the agreement number corresponding to your trading account number.