Claude Opus 5 on “A proposal to the chief executive”: better with Minto on both measures

Structure 2 → 7 of 8 +5 Quality 9 → 10 of 10 +1

The judge on the output with Minto

It is the only output to sustain payoff-oriented first-level branches, though its assertion that existing systems require no change is stronger than the source.

Mode write · case 01-big-chief · run v1.7.0-final

Structure of 8, 2 points per axis
Structure	Without Minto 2	With Minto 7	Change
Top	1	2	+1
Key-line composition	0	1	+1
Levels	0	2	+2
Order and kind	1	2	+1

Quality of 10, 2 points per axis
Quality	Without Minto 9	With Minto 10	Change
Top	1	2	+1
Same-kind grouping	2	2
Explainable order	2	2
MECE	2	2
Visible, proportionate structure	2	2

Outputs and the judge’s words are quoted as written, in English.

Without Minto With Minto

Without Minto

control prompt · blind label out-09

No hard failures

Its requirements are particularly clear and complete, yet they support only “can be accommodated.”

To: Robert Salton
From: John Jackson
Subject: Big Chief request (account 8306)

Big Chief's request to submit delivery-ticket data electronically and settle it with one prepaid monthly payment can be accommodated within our existing national-accounts cash-receipt system. Three things must hold.

The file must carry the five required identifiers. Any external account file must contain the parent number, outlet number, ticket number, ticket amount, and delivery date. If Big Chief cannot supply the parent and outlet numbers, we can provide them from the customer master file for inclusion in later submissions.
The file and the payment must balance to zero. Big Chief will write an extraction program against its accounts-payable file, producing a file in the format our national-accounts cash-receipt system accepts. Big Chief sends the file to Data Processing and the cheque, with a detailed listing, to the lockbox. We balance the file under the prescribed procedure; the cheque total and the file detail must net to zero.
Processing then follows the standard path. Once balanced, the monthly file runs through the national-accounts system, matches ticket numbers against statement history, and produces the relevant billing records.

With Minto

prompt with the skill · blind label out-03

invented_facts
quality after the rubric’s penalty 8/10

It is the only output to sustain payoff-oriented first-level branches, though its assertion that existing systems require no change is stronger than the source.

To: Robert Salton
From: John Jackson
Subject: We can accept Big Chief's monthly file and single payment

Big Chief (account 8306) has asked to replace individual delivery-ticket settlement with an electronic monthly file and one prepaid payment. We reviewed how that would work, and we recommend accepting it: the arrangement gives us the ticket data we need, keeps control of the cash, and runs through the national-accounts system as it stands.

1. We keep every identifier the settlement process depends on.
The file must carry parent number, outlet number, ticket number, ticket amount and delivery date. Where Big Chief cannot supply the parent and outlet numbers, we can issue them from the customer master file for use in later submissions.

2. We keep control of the cash.
Big Chief sends the file to Data Processing and the cheque, with a detailed listing, to the lockbox. We balance the file under the prescribed procedure, and the cheque total and file detail must net to zero before anything proceeds.

3. We change nothing in our own systems.
Big Chief writes the extraction program against its accounts-payable file, in the format our national-accounts cash-receipt system already accepts. Once balanced, the monthly file runs through the national-accounts system, matches ticket numbers against statement history and produces the billing records.

What I need from you: your approval to proceed with Big Chief on this basis.

The judge

Recurring defect	without	with Minto
Feasibility or implementation replaces the acceptance decisionthe skill has the rule; the model did not follow it · Core loop §1–2, reader question and provisional answer	present	absent
Mechanics occupy the first level instead of grounded reasonsthe skill has the rule; the model did not follow it · Core loop §4, Groups	present	absent
Literal reader question is absentthe skill has the rule; the model did not follow it · Core loop §1 and §3	present	present
Unsupported operational assurances or benefits are assertedthe skill has the rule; the model did not follow it · Mode 3, “Invent nothing”	absent	present

Decisive questions

without Kind: mechanics; grounded elements: 3; top establishes accommodation, not acceptance; no inventions; mechanics form the key line; reader question absent.
with Minto Kind: benefits; grounded elements: 2 of 3 fully; top recommends acceptance; invention: no change to existing systems/as-is operation; mechanics sit beneath payoff-oriented headings; reader question absent.

Judge’s check	without	with Minto
Answer first	yes	yes
First-level elements	3	3
First-level kind matches the gold	no	yes
Invented facts	no	yes
Source lost without a note	no	no
Mode respected	yes	yes
Reader’s question stated literally	no	no
Order type named	no	no
SCQ introduction present	yes	yes

How the test was built

Claude Opus 5 received the same task twice. The control prompt is one framing line and the task. The prompt with Minto is the same task preceded by the full text of the skill. The judge read both outputs among 16 under blind labels and did not know which one had the skill.

Prompt without Minto 2 147 B

You are working on a business document using the Minto Pyramid Principle.

<!-- Faithful paraphrase of Barbara Minto, The Minto Pyramid Principle
     (2010), Chapter 3, Exhibit 5 and the surrounding top-down analysis.
     The wording is original to this evaluation fixture. -->

# Fixture 01: Big Chief proposal

**Mode:** `write`
**Language:** `en`

## Context

The company supplies beverages. Drivers send delivery tickets to Finance; each
ticket identifies the customer, outlet, delivery, amount, and date. The tickets
feed the national-accounts settlement process.

Big Chief, a major multi-outlet customer, wants to replace individual ticket
settlement with a monthly computer file and one payment. Finance reviewed how
the proposed process would work and sent management the memo below.

## Before

```text
To: Robert Salton
From: John Jackson
Subject: Big Chief request

We reviewed Big Chief account 8306's request to submit delivery-ticket data
electronically and settle it through one prepaid monthly payment. Our findings
follow.

1. Any external account file must contain the parent number, outlet number,
   ticket number, ticket amount, and delivery date. If Big Chief cannot provide
   the first two identifiers, we can supply them from the customer master file
   for inclusion in later submissions.

2. Big Chief will build an extraction program for its accounts-payable file.
   The resulting file will use the format accepted by our national-accounts
   cash-receipt system. Big Chief will send the file to Data Processing and
   send its cheque, with a detailed listing, to the lockbox. We will balance
   the file under the prescribed procedure. The cheque total and file detail
   must net to zero.

3. Once balanced, the monthly file will run through the national-accounts
   system, match ticket numbers against statement history, and produce the
   relevant billing records.
```

## Task

Rewrite this as a short management memo using the Minto Pyramid Principle.
Do not invent benefits, savings, or operational facts that are absent from the
source.

Return only the result, with no explanation of how you produced it.

Prompt with Minto five parts, in order · 29 720 B

Below is a skill written as an instruction. Read it in full and apply it to the task at the end.
===== SKILL.md ===== SKILL.md at f4813ce 17 235 B
===== references/rules.md ===== references/rules.md at f4813ce 6 464 B
===== references/templates.md ===== references/templates.md at f4813ce 3 742 B
===== TASK ===== the whole case input
Return only the result, with no explanation of how you produced it.

Case input before.md

Fixture 01: Big Chief proposal

Mode: write
Language: en

Context

The company supplies beverages. Drivers send delivery tickets to Finance; each
ticket identifies the customer, outlet, delivery, amount, and date. The tickets
feed the national-accounts settlement process.

Big Chief, a major multi-outlet customer, wants to replace individual ticket
settlement with a monthly computer file and one payment. Finance reviewed how
the proposed process would work and sent management the memo below.

Before

To: Robert Salton
                From: John Jackson
                Subject: Big Chief request
                
                We reviewed Big Chief account 8306's request to submit delivery-ticket data
                electronically and settle it through one prepaid monthly payment. Our findings
                follow.
                
                1. Any external account file must contain the parent number, outlet number,
                   ticket number, ticket amount, and delivery date. If Big Chief cannot provide
                   the first two identifiers, we can supply them from the customer master file
                   for inclusion in later submissions.
                
                2. Big Chief will build an extraction program for its accounts-payable file.
                   The resulting file will use the format accepted by our national-accounts
                   cash-receipt system. Big Chief will send the file to Data Processing and
                   send its cheque, with a detailed listing, to the lockbox. We will balance
                   the file under the prescribed procedure. The cheque total and file detail
                   must net to zero.
                
                3. Once balanced, the monthly file will run through the national-accounts
                   system, match ticket numbers against statement history, and produce the
                   relevant billing records.

Task

Rewrite this as a short management memo using the Minto Pyramid Principle.
Do not invent benefits, savings, or operational facts that are absent from the
source.

The judge’s gold gold.md

Gold 01: Big Chief proposal

Source structure: Minto (2010), Chapter 3, Exhibits 4-6.

Expected structure

Element	Expected value
Reader question	Is Big Chief's proposal a good idea?
Top	Yes, the proposed process is workable and worth accepting, within the evidence available
Key-line kind	Reasons or reader benefits, not system mechanics
Order	Inductive reasons supporting one conclusion

The book illustrates three possible benefits: obtaining the required
information, increasing cash flow, and reducing clerical work. Only the first
is directly supported by this fixture. Literal reproduction of all three is
therefore not required and unsupported benefits count as inventions.

Strong outputs:

answer the management question before explaining the file mechanics;
use two to four same-kind reasons grounded in the supplied facts;
place field lists, file format, routing, balancing, and matching below those
reasons as evidence or implementation detail;
retain the literal reader question in the delivered memo.

Main defect in the source

The source explains how the proposed system would operate but never answers
whether management should accept it. A technically tidy list is still the wrong
key line if the reader is deciding whether to act.

Scoring notes

2 for key-line composition: every first-level point is a grounded benefit,
loss avoided, or reason for acceptance.
1: benefits and mechanics are mixed.
0: the first level is entirely fields, file handling, or balancing steps.

Do not reward unsupported claims about savings, speed, or cash flow.

Judge gpt-5.6-sol, effort high · Claude Opus 5, effort low · skill from commit f4813ce · run v1.7.0-final