Hi @Jonathan Mann · Welcome to Q&A platform and thank you for your query.
Any unused connectors/agents are tagged as inactive and are removed automatically after 10 days of inactivity.
This is not explicitly documented for Azure AD Provisioning Agent but it is documented under Maintenance section of Understand Azure AD Application Proxy connectors document.
@Andy David - MVP the delete option you are referring to is to delete the configuration. On the Agents page, there is no delete option:
-----------------------------------------------------------------------------------------------------------
Please "Accept the answer" if the information helped you. This will help us and others in the community as well.