Same Model, Different Harness: CUGA, Hermes, and Deep Agents — When to Pick CUGA?

IBM ran CUGA, Hermes, and Deep Agents on the same open-weight model (GLM-5.3-flash) across 90 AppWorld tasks, and task completion ranged from 30% to 81% depending only on the harness, with CUGA at 81.1% (73/90) versus Hermes at 46.7% and Deep Agents at 30.0%. CUGA is IBM's Apache 2.0 harness for enterprise API work, adding runtime-enforced policies (intent guards, tool approvals, ToolGuards, output formatting) and deployment inside sovereign or air-gapped environments. The authors note the 90-task sample, non-identical setups, and absence of policy testing as limits, and say CUGA is not the right fit for terminal coding or personal chat assistants.