Problem
Multi-agent systems depend on an orchestrator correctly splitting a task's information among sub-agent roles: which fragment goes to which role, what each sub-agent is and is not told, and how that translates into the literal prompt text each sub-agent receives. End-to-end evals (execution success, tool-call correctness) and topology definitions (who talks to whom) both assume this hand-off step is done correctly, but neither tests it directly. A sub-agent can still stumble through a task with an incomplete or wrongly-scoped prompt, masking an orchestration bug until the system is scaled to harder tasks or unfamiliar topologies, where mis-assigned information becomes the dominant failure mode.
Solution
Treat "writing correct sub-agent prompts" as a skill to benchmark on its own, separate from whether the end task ultimately succeeds. For each of a set of scenarios spanning distinct communication topologies:
- Define the ground-truth information fragments required for the task and the role that legitimately needs each fragment.
- Ask the orchestrator LLM to decompose the task and write the actual prompt text for every sub-agent role in that topology.
- Score each generated sub-agent prompt against the ground truth: did it receive every fragment its role needs (recall), does it withhold fragments that role should not see (leakage), and is each fragment routed to the correct role rather than a neighboring one (assignment accuracy)?
- Aggregate scores per topology to see where orchestration quality degrades — chain and star topologies typically stress this less than deeper tree or mesh topologies with many-to-many hand-offs.
This is deliberately orthogonal to Workflow Evals with Mocked Tools (scores whether the right tools get called) and to Declarative Multi-Agent Topology Definition (specifies the agent graph but not whether prompts populate it correctly). It is closer to a unit test for the hand-off step itself.
How to use it
- Use when you are building or hardening a multi-agent system and want a regression suite for the orchestrator's delegation quality, not just final output quality.
- Write a handful of scenarios per topology you actually use (chain, star, tree, fan-out/fan-in, debate, mesh); you do not need every topology to get value.
- Score three things per generated sub-agent prompt: required-fragment recall, forbidden-fragment leakage, and role-assignment accuracy.
- Run this alongside — not instead of — end-to-end workflow evals; it catches a different class of bug (mis-delegation) than tool-call or output-format evals do.
- Re-run whenever you change the topology or swap the orchestrator model.
Trade-offs
Pros:
- Isolates delegation-quality bugs that end-to-end evals otherwise blame on the wrong sub-agent.
- Topology-indexed scoring shows exactly where orchestration degrades as systems scale past simple chains/stars.
- Cheap to extend: new scenarios are just (topology, fragments, ground-truth assignment) tuples.
Cons:
- Requires hand-authoring ground-truth fragment/role assignments per scenario, which does not scale automatically to a new domain.
- A single benchmark; treat absolute scores as directional until independently replicated.
- Does not replace end-to-end evals — a system can score well here and still fail downstream for unrelated reasons (bad tools, bad models).
References
- Sun, Y. et al. PerspectiveGap: A Benchmark for Multi-Agent Orchestration Prompting. arXiv:2606.08878. Code: https://github.com/WhymustIhaveaname/PerspectiveGap.
- Related: Declarative Multi-Agent Topology Definition — defines the agent graph this pattern tests prompt hand-offs against.
- Related: Subject Hygiene for Task Delegation — traceability of task subjects; this pattern instead tests information-content correctness of the delegation itself.
- Related: Workflow Evals with Mocked Tools — complementary eval angle (tool-call correctness vs. delegation-prompt correctness).
- Related: Sub-Agent Spawning — describes how the main agent creates the sub-agent invocations this pattern scores; this pattern checks whether those invocations actually carry the right information.
- FIPA. "FIPA ACL Communicative Act Library Specification." 2002 — theoretical foundation for structured inter-agent communication that this benchmark operationalizes as a measurable score.