/auto-agent-eco

Spawn subagents one tier below the model doing the orchestrating. The expensive model decides, routes and merges; cheaper models do the legwork.

Usage: /auto-agent-eco — the agent count is yours to judge. /auto-agent-eco 6 — a hard ceiling of six subagents.

The Rule

Read the model this session is running as, then cap every subagent strictly below it:

Note the asymmetry: from Fable, the ceiling drops a full tier — that is the entire point of eco mode, and it is where the saving comes from. From Opus and below, "strictly below" would leave nothing useful to route to on hard subtasks, so same-tier is permitted and the discipline becomes routing rather than capping. Do not spawn a peer out of habit; spawn one when the subtask genuinely needs that tier.

If the session's model cannot be determined, assume the tier below your best guess and say which assumption you made. Guessing high spends the user's money on an assumption they never agreed to.

Where The Saving Actually Comes From

Not from making everything cheap. From splitting the work by kind:

• The orchestrator keeps the judgment — deciding what the subtasks are, spotting when a result is wrong, reconciling contradictions, and writing the synthesis. That work is dense, short, and the worst possible thing to hand to a cheap model.
• Subagents get the volume — reading files, tracing call sites, running greps and builds, drafting mechanical edits, gathering evidence. That work is long, parallel, and mostly legwork.

A pass that hands twelve files to a cheap model and one paragraph of conclusions to the expensive one costs a fraction of a uniform fan-out and loses very little. A pass that hands the conclusions to the cheap model saves nothing worth having, because the orchestrator then re-does the thinking.

Routing, By What The Task Actually Needs

What Eco Mode Must Not Downgrade

Cheap models fail in a specific way: they produce output with the shape of a correct answer. A plausible file:line that does not exist, a confident "verified" with nothing behind it, an edit that compiles and does the wrong thing. That failure mode is invisible to a merge that trusts its inputs.

So three things stay expensive regardless of budget:

1. Adversarial verification. If a finding is going to be acted on, whatever tries to refute it must be at least as capable as whatever produced it. Cheap verification of cheap work is theatre.
2. Security and correctness judgments. "Is this exploitable", "does this actually hold" — wrong answers here cost far more than the tokens saved.
3. The merge. The orchestrator reads every subagent result critically and never pastes them together. A contradiction between two subagents is a finding, not a formatting problem.

Eco means cheaper, not credulous. If economising would mean shipping an unverified claim, spend the tokens or report the claim as unverified — the third option, quietly lowering the standard, is the one this skill exists to prevent.

The Agent Count

A number after the command is a hard ceiling: /auto-agent-eco 6 means never more than six, and it wins over your own judgment.

With no number, choose from the work and the machine, and say what you chose and why. Two constraints bound it and the tighter one wins:

• Resource limits are not negotiable by a cost policy. If /auto-balance has sized this session, its number is a ceiling this skill cannot raise — a cheaper model still occupies a slot, still contends for the same machine, and still counts against account limits. Eco mode reduces cost per agent; it does not create capacity.
• Fewer, longer-lived agents beat many short ones, for coherence and for limits. Splitting one coherent investigation across six agents costs more than it saves, because each rediscovers the same context.

Report What The Policy Cost

At the end, state the fan-out honestly: how many subagents, at which tiers, and — this is the part that matters — anything you routed to a cheaper tier that you would have given a better model with no budget. That is the user's information, not yours to absorb silently. If a cheap agent's output looked thin and you accepted it anyway, say so.

Rationalization Table

Red Flags — Stop

• Spawning a peer-tier subagent from the top tier, which is the one thing eco mode forbids
• Verifying cheap output with something equally cheap
• Pasting subagent results together instead of reading them against each other
• Exceeding a user-supplied ceiling, or treating /auto-balance's number as advisory
• Reporting a clean result without saying which parts ran on a downgraded model
• Downgrading a security or correctness judgment to save tokens