The Orchestra
The Orchestra
A walkable map of the seven roles that make a multi-agent system. Each station is a job, an artifact, and a cue to the stations it can actually combine with.
Seven stations. Ten combination cues. Original editorial work by Agent Chimera. Quotations belong to the linked sources. Independent publication, not affiliated with Anthropic, OpenAI, Cognition, or Microsoft.
The score
Walk the chimera
All seven stations are open below. JavaScript turns this map into a walk.
Control · station 01
Lead
The conductor
How does a lead agent combine specialized workers?
Returns
Task brief, acceptance checklist, synthesis, stop decision.
Cue
The lead cues workers; workers do not cue each other into existence.
The combination earns its keep
- The subtask list cannot be known before the input arrives.
- Workers can return cited notes, patches, tests, or classifications the lead can check.
- The lead keeps the original question in view and can request a focused retry.
The combination is theater
- The lead only forwards messages and never scores coverage or quality.
- Workers return prose instead of artifacts, so synthesis is a guessing game.
- The system spawns specialists for a task one agent already handles.
How this station combines
justified · Lead × Research
Orchestrator-workers
The lead decomposes a breadth-first question, briefs each worker with an objective and a boundary, and synthesizes cited notes. Anthropic's research system is this combination in production, with a reported 90.2% internal-eval gain and about 15× chat-token use. It fails when the brief is a slogan and three workers run the same search.
conditional · Lead × Builder
Scoped implementation
The lead may discover that the file list is unknown and assign one builder a scoped patch. Anthropic names this as an orchestrator-worker fit. Cognition's warning still applies: do not assign two builders to invent the same feature in parallel. The combination is one implementer plus a lead that can read the diff.
justified · Lead × Policy
Guardrail beside the work
A separate instance screens the request or the action while the lead or worker does the task. Anthropic lists this as a parallelization pattern and says it tends to beat one call doing both jobs. The policy artifact is allow, deny, transform, or escalate — not an essay about caution.
justified · Lead × Verifier
Acceptance, not vibes
The lead owns the question; the verifier owns whether an artifact answers it. If the lead cannot fail worker output, orchestration is theater. Anthropic's research lead decides whether more search is needed; the citation agent then checks the report. Those are two different acceptance jobs, and both are required.
Anthropic's practical guide treats orchestrator-workers as a workflow for tasks whose pieces cannot be listed in advance. Coding changes whose file list depends on the request, and search jobs whose sources depend on the question, are the examples they give. The topology looks like a team. The control path is still a lead that assigns, waits, and merges.
Anthropic's research system is the production version of that sketch: a lead plans, saves the plan, and spawns specialized subagents. The lead is also the place that can decide the work is done. That stop condition is part of the role. Early versions of that system spawned dozens of workers for simple queries; the fix was teaching the orchestrator how to delegate, not adding another layer of managers.
Cognition's critique still applies at this stand. If the lead hands out vague slices and never shares the decisions those slices depend on, the workers will invent incompatible worlds. The conductor is accountable for the brief. A one-line instruction such as "research the semiconductor shortage" is how you get three workers doing the same search.
"subtasks aren't pre-defined, but determined by the orchestrator based on the specific input"
Anthropic distinguishes orchestrator-workers from fixed parallelization: the lead invents the work list from the request, then synthesizes.
Workers · station 02
Research
The search desks
When do parallel research agents actually help?
Returns
Cited notes: claim, source, date, confidence, open question.
Cue
Research combines with a lead that can score coverage, and with memory that stores the notes.
The combination earns its keep
- The question has independent directions that do not share a single source trail.
- Each worker has a distinct source class, time window, or entity list.
- Findings return as citations the lead and a later citation pass can audit.
The combination is theater
- Several workers run the same query with different names.
- The lead asks for "everything about X" and hopes specialization emerges.
- Notes are summarized so hard that quotes, URLs, and dates disappear.
How this station combines
justified · Research × Lead
Orchestrator-workers
The lead decomposes a breadth-first question, briefs each worker with an objective and a boundary, and synthesizes cited notes. Anthropic's research system is this combination in production, with a reported 90.2% internal-eval gain and about 15× chat-token use. It fails when the brief is a slogan and three workers run the same search.
justified · Research × Memory
Artifacts, not telephone
Workers write notes to an inspectable store and return a pointer. Anthropic describes this as the way to avoid a game of telephone and to stop copying large outputs through the lead's history. If the notes lose URLs, quotes, and dates, memory has already failed.
justified · Research × Verifier
Citation after synthesis
After the lead synthesizes, a citation pass grounds claims against the notes and source documents. Anthropic's research system includes this specialist so synthesis cannot smooth away provenance. Skipping it because the report "sounds sourced" is how citations die.
The clean combination is breadth-first research. A question such as "list the board members of every Information Technology S&P 500 company" is a pile of independent lookups. Anthropic's lead could decompose that; a single sequential agent could not finish. That is a task-shape argument, not a maturity badge.
The same post is honest about the bill. Multi-agent systems in their data used about fifteen times the tokens of chat. They also say domains that require shared context, including most coding, are a poor fit today. If you quote 90.2% without 15×, you are not reading the score.
Delegation quality is the difference between an orchestra and a crowd. Anthropic had to specify objective, output format, tools, and boundaries after short instructions caused duplicated work. Human testers still caught a bias toward SEO content farms over primary sources. The research desk is only as good as the source rule in its brief.
"a multi-agent system with Claude Opus 4 as the lead agent and Claude Sonnet 4 subagents outperformed single-agent Claude Opus 4 by 90.2% on our internal research eval"
Anthropic reports this as an internal research-eval result for breadth-first queries, not as a universal multi-agent law. The same post reports about 15× chat-token use.
Workers · station 03
Builder
The instrument shop
Can builder agents combine in parallel on the same change?
Returns
Scoped patch: files, why each change is in scope, leftover risk.
Cue
A builder combines with a verifier and a lead. Two builders on one change usually fight.
The combination earns its keep
- The file list is unknown until the request is inspected, and one worker owns the patch.
- A separate agent answers a well-bounded question without writing code.
- Verification is independent: tests, browser checks, or a rubric the builder does not grade.
The combination is theater
- Two implementers split a coupled feature and meet in a merge conflict of taste.
- The builder is asked to "own frontend" forever instead of a named artifact.
- The lead never reads the patch and treats a green chat message as a ship.
How this station combines
conditional · Builder × Lead
Scoped implementation
The lead may discover that the file list is unknown and assign one builder a scoped patch. Anthropic names this as an orchestrator-worker fit. Cognition's warning still applies: do not assign two builders to invent the same feature in parallel. The combination is one implementer plus a lead that can read the diff.
justified · Builder × Verifier
Evaluator-optimizer
One agent writes a patch; another runs tests, browser checks, or a rubric and can fail the artifact. Anthropic's evaluator-optimizer workflow is this pair, and it needs clear criteria plus evidence that the extra pass helps. A sibling who "reviews" in the same prompt is not a verifier.
fragile · Builder × Builder
Parallel implementers
Almost never. Cognition's Flappy Bird example is the score for this cue: one worker builds the wrong world, the other builds an incompatible sprite, and the lead is asked to make them one product. Independent question-asking is the safer extra agent. Coupled edits stay on one thread.
Anthropic's agent guide still lists coding products that change many files as an orchestrator-worker example, because the file list is not known up front. That is compatible with a single builder under a lead. It is not a license for two builders to invent the architecture in parallel.
Cognition's June 2025 critique is the required counterweight. Sharing the original prompt is not enough once tool calls and multi-turn decisions have happened. Actions encode taste, naming, and structure. Two unseen builders will not converge on those. Their recommended default is a single-threaded agent; extra agents, if any, answer questions so the main trace stays short.
On this map, the builder is therefore a specialist with a tight contract: change the files named in scope, or justify an extra file in the patch notes. The verifier, not a sibling builder, is the combination that pays.
"Actions carry implicit decisions, and conflicting decisions carry bad results"
Cognition's Flappy Bird example is the anti-combination: one worker builds Mario pipes, another builds an off-style bird, and the lead is asked to make them one game.
Workers · station 04
Verifier
The pit critic
How does a verifier combine with the agents that generate work?
Returns
Report: commands, results, remaining risk, pass or fail against the brief.
Cue
The verifier cues a retry or a stop. It does not decorate a pass.
The combination earns its keep
- There is a rubric a human would use, and the extra pass has been shown to catch misses.
- The verifier can reach ground truth: tests, files, citations, or a policy list.
- Failing the artifact is cheaper than shipping it, and the lead honors a fail.
The combination is theater
- The judge is the same prompt with "be critical" appended.
- Three agents vote without external evidence and call the majority truth.
- The citation pass is skipped because the lead already "sounds sourced."
How this station combines
justified · Verifier × Builder
Evaluator-optimizer
One agent writes a patch; another runs tests, browser checks, or a rubric and can fail the artifact. Anthropic's evaluator-optimizer workflow is this pair, and it needs clear criteria plus evidence that the extra pass helps. A sibling who "reviews" in the same prompt is not a verifier.
justified · Verifier × Research
Citation after synthesis
After the lead synthesizes, a citation pass grounds claims against the notes and source documents. Anthropic's research system includes this specialist so synthesis cannot smooth away provenance. Skipping it because the report "sounds sourced" is how citations die.
justified · Verifier × Lead
Acceptance, not vibes
The lead owns the question; the verifier owns whether an artifact answers it. If the lead cannot fail worker output, orchestration is theater. Anthropic's research lead decides whether more search is needed; the citation agent then checks the report. Those are two different acceptance jobs, and both are required.
The verifier is how specialized agents stay honest. Anthropic's building-effective-agents post names evaluator-optimizer as its own workflow, useful when a human's feedback would help and a model can give that feedback. Translation and multi-round search are their examples. The two signs of fit are a clear rubric and measurable improvement.
The research system adds a later specialist: a citation agent that grounds claims after the lead synthesizes. That is a verifier with a narrow artifact. It exists because synthesis is where sources get smoothed away. If your multi-agent design has no equivalent pass, the lead is grading its own homework.
MetaGPT is on this stand as a warning, not as a product recommendation: cascading hallucinations are the failure mode of naive chaining. A verifier that cannot fail the previous artifact is another chain link.
"This workflow is particularly effective when we have clear evaluation criteria, and when iterative refinement provides measurable value"
Evaluator-optimizer is a named Anthropic workflow: generate, evaluate, loop. It is not a swarm, and it needs a rubric.
Control · station 05
Policy
The house rules
Why separate policy from the agent doing the work?
Returns
Decision: allow, deny, transform, or escalate, with the rule that fired.
Cue
Policy combines as a parallel screen or as a handoff at a trust boundary.
The combination earns its keep
- The action can spend money, change production state, or cross a permission line.
- A separate prompt or deterministic checker is better at the rule than the worker is.
- The output is a structured decision the lead cannot quietly ignore.
The combination is theater
- The worker is asked to "be safe" inside the same prompt that does the task.
- Policy replies in essay form, so nobody can tell what was allowed.
- A human gate exists on the diagram and is never invoked in the trace.
How this station combines
justified · Policy × Lead
Guardrail beside the work
A separate instance screens the request or the action while the lead or worker does the task. Anthropic lists this as a parallelization pattern and says it tends to beat one call doing both jobs. The policy artifact is allow, deny, transform, or escalate — not an essay about caution.
conditional · Policy × Handoffs
Trust-boundary transfer
A handoff across a permission, spend, or tool boundary should carry blocked actions and an escalation rule, not just the user's original sentence. OpenAI treats such boundaries as a reason to split after maximizing one agent. Without a return path, the receiving agent either stalls or exceeds its mandate.
OpenAI's builder guide is the other source on this stand: maximize one agent first, then split when prompts or tools become unmanageable, or when a manager or handoff pattern is required. Policy and tool overload are valid split reasons. Fashion is not.
The useful combination is boring. A classifier, a permissions check, a spend cap, or a human approval sits beside the worker. Anthropic notes that specialized attention on one consideration tends to beat a single overloaded call. That is sectioning, not a swarm.
On this map, policy is drawn in the danger color because a missing gate is how multi-agent systems become expensive and irreversible. The artifact is a decision record, not a vibe of carefulness.
"Implementing guardrails where one model instance processes user queries while another screens them for inappropriate content or requests"
Anthropic lists this as a parallelization example, and says it tends to beat asking one call to do both the work and the screen.
State · station 06
Memory
The score
How should specialized agents share state?
Returns
Task state: claim, source, owner, timestamp, decision, next action.
Cue
Memory is the score every station reads from. Without it, the map is seven solos.
The combination earns its keep
- The plan and the artifacts outlive a single context window.
- Workers write structured results somewhere inspectable and pass a pointer back.
- A later agent can see the decision, not only a summary of the mood.
The combination is theater
- A vector store of leftover chat is treated as shared understanding.
- Each worker keeps a private novel and sends the lead a paragraph.
- The plan lives only in the lead's context and vanishes at truncation.
How this station combines
justified · Memory × Research
Artifacts, not telephone
Workers write notes to an inspectable store and return a pointer. Anthropic describes this as the way to avoid a game of telephone and to stop copying large outputs through the lead's history. If the notes lose URLs, quotes, and dates, memory has already failed.
justified · Memory × Handoffs
Traces travel with the work
A handoff that does not carry the relevant trace is a new agent being asked to guess. Cognition's first principle is to share context and full traces, not isolated messages. The score and the cue sheet are one object: state that a later agent can act on without reinventing decisions.
Anthropic's research lead writes its plan to memory because a 200,000-token window will truncate, and the plan is not an optional souvenir. That is the difference between memory as a product feature and memory as a survival mechanism for long jobs.
Cognition's first principle belongs on the same stand: share context, and share full traces, not isolated messages. Their second principle explains why: actions carry implicit decisions. A memory that stores only the user's original sentence has already dropped the tool-call trail that interpreted it.
The Orchestra treats memory as the score. Research notes, patches, test reports, and policy decisions are staves. If you cannot point to the bar a later agent is playing from, you do not have a multi-agent system. You have several chats.
"Subagents call tools to store their work in external systems, then pass lightweight references back to the coordinator"
Anthropic names this as the way to avoid a game of telephone and to stop copying large outputs through conversation history.
State · station 07
Handoffs
The cue sheet
How should work move from one specialized agent to another?
Returns
Transfer record: goal, state, constraints, blocked actions, return rule.
Cue
Handoffs combine stations without asking them to share a brain.
The combination earns its keep
- A different tool set, policy, or context window genuinely owns the next step.
- The receiving agent gets the decisions, not a slogan about the task.
- There is a path back when the receiving agent is blocked.
The combination is theater
- Agents "talk it out" the way humans resolve merge conflicts, with no contract.
- The sender compresses a 40-turn trace into a vibe and calls it context.
- Ownership is unclear, so two agents keep working the same file.
How this station combines
justified · Handoffs × Memory
Traces travel with the work
A handoff that does not carry the relevant trace is a new agent being asked to guess. Cognition's first principle is to share context and full traces, not isolated messages. The score and the cue sheet are one object: state that a later agent can act on without reinventing decisions.
conditional · Handoffs × Policy
Trust-boundary transfer
A handoff across a permission, spend, or tool boundary should carry blocked actions and an escalation rule, not just the user's original sentence. OpenAI treats such boundaries as a reason to split after maximizing one agent. Without a return path, the receiving agent either stalls or exceeds its mandate.
OpenAI's guide puts handoffs late: after a single agent is doing real work, and after prompt or tool complexity, manager patterns, or policy boundaries make a split rational. That order matters. A handoff graph drawn before a working single agent is choreography.
AutoGen is here because it is a research framework for composing conversable agents with models, tools, code, and humans. It is evidence that conversation can be a coordination medium. It is not evidence that conversation is sufficient. The useful residue is the same as everywhere else on this map: who can call tools, what they must return, and when a human enters.
Anthropic's research post notes that their lead still runs subagents synchronously, waiting on each set before continuing. Even a sophisticated production system has not made free-form agent chat the coordination layer. If you need asynchrony, you are taking on state consistency as a product problem, not unlocking a higher form of intelligence.
"Share context, and share full agent traces, not just individual messages"
Cognition treats this as principle 1 of production agents. A handoff that forwards only the latest chat line violates it on purpose.
Evidence on the stand
The two numbers the map has to hold at once
Why an orchestra, not a swarm poster
A chimera is only a useful metaphor if the parts share enough state to act like one organism. An orchestra is the same idea with a stricter picture: specialized sections, a conductor who can still hear the piece, a written score, and cues that say when another section is allowed to enter. Extra musicians are not a flex. They are a cost that has to improve the music.
That is why this page is a walkable map of roles rather than a catalog of vendor diagrams. The patterns page already names orchestrator-worker, pipeline, debate, swarm, and hierarchy. The Orchestra asks a prior question: which jobs are actually staffed, what each job must return, and which pairs are justified, conditional, or fragile. A swarm poster that cannot answer those three questions is decoration.
The first eighty words are the answer because that is how the question arrives — from a person choosing an architecture, or from a model retrieving a citation. The cap is enforced at build time. If a station answer grows past eighty words, this page does not compile.
House rules
What this map will not do
Earn the split
The Orchestra is not a pitch for more agents. One well-tooled agent is the default. A second role enters only when it returns a checkable artifact the first agent could not produce alone.
Both camps, on the stand
Anthropic's research result and Cognition's context-fragmentation warning sit in the same score. A station that cites one without the other is out of tune.
No invented results
Figures such as 90.2% and 15× are Anthropic's reported measurements on named internal evals, not independent replications. This page does not invent prices, protocols, or paper results.
Independent
Agent Chimera is an independent educational publication and is not affiliated with Anthropic, OpenAI, Cognition, Microsoft, or any cited organization.
Credit
What is theirs, what is ours
Original work
The station names, combination verdicts, and editorial synthesis are original work by Agent Chimera. Cite them as ours, not as the papers they discuss.
Their words, linked
Every quotation on a stand is from a named primary source, with title, date, and URL. We do not rewrite a source into a fake quote.
Roles, not products
Lead, research, builder, verifier, policy, memory, and handoffs are jobs. They are not vendor SKUs, and they do not require a particular framework.
Sources used on this page
Anthropic / 2024-12-19
Building effective agents
Defines workflows vs agents and recommends starting with the simplest solution that meets the task.
Anthropic / 2025-06-13
How we built our multi-agent research system
Concrete pro case for breadth-first research, with reported 90.2% internal eval gain and about 15x chat token use.
Cognition / 2025-06-12
Don't Build Multi-Agents
Argues that parallel agents are fragile when context and implicit decisions are not shared thoroughly.
OpenAI / 2025
A practical guide to building agents
Recommends maximizing one agent first, then splitting for prompt complexity, tool overload, manager patterns, or handoffs.
Microsoft Research / 2024-08
AutoGen: Enabling Next-Gen LLM Applications via Multi-Agent Conversation
Documents a framework for composing conversable agents with LLMs, tools, code, and human input.
Du et al. / 2023-05-23
Improving Factuality and Reasoning in Language Models through Multiagent Debate
Studies multiple model instances that propose, critique, and converge over debate rounds.
Hong et al. / 2023-08-01
MetaGPT: Meta Programming for A Multi-Agent Collaborative Framework
Frames cascading hallucinations as a core risk and uses SOP-style workflows to reduce errors.
Li et al. / 2023-03-31
CAMEL: Communicative Agents for Mind Exploration of Large Language Model Society
Introduces role-playing communicative agents for studying cooperative behavior in multi-agent settings.