Agents will disrupt the group in various ways. It will be in the guise of beneficial acts.

One way to detect them is to see what the results of their actions are. Never mind what their stated intention is, as it will not align. They will always appear to be loyal and hardworking for the cause. However, when the results of their actions undermines the cause over and over, there's a chance it's intentional. Sure, they could just be really inept, or unusually unlucky, but if so, that needs to be mitigated as well.

They also like to encourage disagreement, (again, for supposed "benevolent" reasons), but it's part of creating division to reduce momentum in the movement.

After seeing agents do their work in cannabis legalization organizations, I started identifying the traits later when I joined other organizations. They work from the same playbook.