The right answer is usually where work already happens
Discord and Slack can run similar AI backbones. The deciding factor is not model quality. It is where the team will actually use the assistant.
If everyone already coordinates projects in Discord, put the agent there. If the company lives in Slack and the admin model matters, use Slack.
Discord is faster, Slack is more formal
Discord is often the better fit for lean teams that want channels turned into workspaces quickly. It is informal, fast, and familiar to many creator-led teams.
Slack is better when the deployment needs to fit into workplace norms: admin approval, OAuth scopes, channel policy, retention, and internal operations.