A publishing agent is a software agent designed to publish updates to designs automatically. It runs the publication as an automation, which allows synchronization of data from an authoring tool to a SECollab design.
The activation column gives out the current state of the agent, and allows for enabling or disabling the agent.
Enabling a Mantis agent is required to trigger a manual publication. However the automated publication isn't dependent upon this column. This is because the Mantis server is triggering the interaction. It is possible to disable Agent associations individually.
For a user to be allowed to trigger a manual publication through an agent, he needs to be a member of the project and be assigned the following permission: Publish or modify designs.
For an automatic publication, that same user also needs to be assigned the permission Trigger publishing event by agent. In such cases, the user attached to the agent or to the consumer key is usually a service account.