Is intention required when giving Zakat, given that my father will give it on my behalf?

It is permissible for a person to appoint another as an agent to disburse Zakat (whether Zakat on wealth or Zakat al-Fitr). The original ruling is that the principal (the one giving Zakat) should make the intention when handing the Zakat to the agent, and the agent should make the intention when distributing it. If the principal makes the intention when handing it over, but the agent does not make the intention when distributing it, this is sufficient according to some scholars. However, the more cautious approach is for both to make the intention. Therefore, what is required of you is to make the intention for Zakat when you appoint your father, and he must make the intention when he disburses it.