From f0a5086dbc6890680d2a95eab52a86e136431a30 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Padez?= Date: Tue, 25 Aug 2026 03:50:49 +0000 Subject: [PATCH] delegating: which model, and why cheapest alone is wrong MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit haiku for mechanical, sonnet by default, opus only when the work still holds a decision — which usually means the brief needs finishing rather than a bigger model writing it. and the part that matters: cheapness is a property of the pair, not the model. a cheap model on a vague brief is the most expensive option available — it returns something plausible, you reject it, you write the brief you should have written, and you pay for the round twice. Co-Authored-By: Claude Opus 5 Officer-Session: 656f5c85-e49a-4f1f-b9f3-042a04b4d043 --- skills/delegating/SKILL.md | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/skills/delegating/SKILL.md b/skills/delegating/SKILL.md index e4dd1f6..44c6ba0 100644 --- a/skills/delegating/SKILL.md +++ b/skills/delegating/SKILL.md @@ -44,6 +44,28 @@ An agent that has to ask a question has already cost more than it saved. So the Run it in the background and carry on. A brief good enough to run unattended is the same brief that makes the result reviewable. +# Choosing the model + +**The cheapest one that will get it right.** Not the cheapest one; the cheapest one that will get it +right, which is a different question and has to be asked per task. + +- **Haiku** — mechanical and high-volume with no judgement in it. A rename across forty call sites, a + JSON transform, moving a block of files to a new shape. +- **Sonnet** — the default, and what most of this work is. A feature whose design is settled and whose + brief names the files: translations, a form, tests for a rule already agreed, a migration over a list. +- **Opus** — when the work still contains a decision. Which usually means the brief is incomplete, so + the first move is to finish the brief rather than to spend more per token on writing it. + +## Cheapness is a property of the pair, not the model + +A cheap model on a vague brief is the most expensive option available: it returns something plausible, +you review it, you reject it, you write the brief you should have written, and you pay for the whole +round twice. The saving comes from the brief being good enough that a smaller model cannot go wrong — +so if you find yourself reaching for a bigger model to compensate for a thin brief, fix the brief. + +The other direction is real too, and cheaper to correct: a task that comes back wrong from Haiku goes to +Sonnet and costs one wasted run. Start low. + # Reviewing what comes back **Read the diff, not the summary.** The summary is written by the thing being reviewed. `git diff` is not.