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A three-agent CrewAI run spent 44.6 of its 118 seconds inside coworker tool calls

CrewAI hands a delegating agent two functions. Calling one starts a fresh model call as the named coworker. In this run the expensive reviewer caught a price error it had no source to check.

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Illustration accompanying A three-agent CrewAI run spent 44.6 of its 118 seconds inside coworker tool calls

What happened

  • The Editor queried a $1,600 home AI server price in the draft, and the Analyst replied that $1,600 buys the graphics card alone while a complete machine runs $2,500 to $3,500.
  • The activity log lists three entries: two ask_question_to_coworker calls at 15.3 and 20.4 seconds, and one delegate_work_to_coworker call at 8.9 seconds.
  • Neither agent had web access, so the Analyst produced the corrected figures from the same kind of training data that produced the number it was correcting.

Compiled by The EngineerSomething wrong?How this is made

Why it matters

  • cost Every delegated question runs the callee's model from scratch, so a reviewer that opens several rounds multiplies calls on the cheap agents' accounts while the expensive agent only reads the returns.
  • constraint Improving the quality of the crew's discussion means engineering what each call passes in, because no shared state exists for an agent to consult.
  • exposure A reviewer with no retrieval can only trade one model's guess for another's, so the replacement figure ships with the same evidentiary standing as the number it displaced.
  • decision Anyone budgeting a crew has to price the review pass at roughly 38 percent of wall clock before a single retrieval tool is attached.

When a CrewAI agent is allowed to delegate, the framework registers two extra functions on it, ask_question_to_coworker and delegate_work_to_coworker [15]. They arrive the same way a web search or a file reader would [15]. Call the first with a coworker's name, a question and some context, and CrewAI starts a fresh model call as that coworker; whatever comes back reaches the caller as the tool's result [16]. "A conversation between agents isn't a conversation. It's a function call with a job title," the post's author wrote [17]. So the Editor's challenge to the $1,600 figure was a tool invocation, and the Analyst's rebuttal was that tool's return value.

The three logged durations add up to 44.6 seconds [21]. That is about 38 percent of the 118-second run [22]. Each of those calls is a model invocation on top of the three sequential tasks, so the run made at least six [23]. The post reports 14,609 tokens in and 3,928 out for the run as a whole and does not break them down by agent or by call [10][27].

The model split is the deliberate part. Analyst and Writer on Qwen 3 235B through OpenRouter, Editor on Claude Opus 4.8 direct from Anthropic [3]. "The cheap model does the volume; the expensive one makes the judgement calls," the author wrote [4]. Because the coworker's own model generates the answer, the Editor's two questions ran as the Analyst [16]. How well that transfers depends on how many rounds your reviewer opens, and this run logged three calls and one caught error [14][13].

CREWAI_DMN=true does not appear in crewai --help; the author found it in the CLI's source, where it switches off every interactive prompt [6]. It also stops the scaffold writing your .env, so the keys are yours to add [7]. The --provider flag only chooses the starting model written into each agent's file [8]. The project itself is plain JSON, one file per agent and one crew.jsonc for the tasks [9].

The check on the correction happened inside the models. The crew had no web access, so the Analyst confirmed the new numbers from the same kind of training data that produced the $1,600 [19]. "A second model agreeing is a second opinion, not a second source," the author wrote [20]. The $2,500 to $3,500 range and the claim that a single 24 GB card cannot run a 70-billion-parameter model at usable speed are plausible and unverified [12][19].

Nothing is shared between agents except what one call gives the next, and the task handoffs work the same way, each task's output pasted into the next task's prompt [18]. The Editor only knew about the $1,600 because it sat in the draft it was handed, and the Analyst could only answer what the question contained [29].

What to watch

  • Whether the same crew with a web search tool attached changes the Analyst's answer on the $2,500 to $3,500 range.
  • Whether CrewAI documents CREWAI_DMN in crewai --help in a release after 1.15.21.
  • Per-agent token accounting in the run output, so the adjudication step can be priced on its own.
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