When to use it

The advisor fits these configurations:

• You currently use Sonnet on complex tasks: Add a higher-tier advisor. Opus keeps total cost similar or lower; Claude Fable 5.1 maximizes the quality lift.
• You currently use Haiku and want a step up in intelligence: Add an Opus or Fable advisor. Expect higher cost than Haiku alone, but lower than switching the executor to a larger model.

Results are task-dependent. Evaluate on your own workload.

The advisor is a weaker fit for single-turn Q&A (nothing to plan), pure pass-through model pickers where your users already choose their own cost and quality tradeoff, or workloads where every turn genuinely requires the advisor model's full capability.