A Book of Criteria is the document where a company writes down the rules it decides by, in plain language, with versions and approved by a person. Your AI agents need it because, without that institutional knowledge in writing, they answer with what seems plausible and not with the company's own judgement.
This article is part of AI-First hybridisation consultancy.
In short
- An AI model knows a great deal in general and nothing about how your company decides.
- The Book of Criteria captures those decisions as rules, each with its reason and its source.
- No rule counts until a person has reviewed and approved it.
- When a rule changes, it changes for every agent at once.
- You start with the rules of a single process.
What a Book of Criteria is
A Book of Criteria is the place where a company's decision rules are written down: what is done in each situation, why, and who approved it. It is institutional knowledge in the form an agent can use most, because it tells the agent what to do in each case.
Almost no company has one. The judgement is spread across a few people, old emails and exceptions nobody noted. While those people do the work, it holds. When part of the work moves to an agent, whatever is not written down disappears. That is why company hybridisation with AI starts by writing it.
At Legathum, the Book of Criteria lives inside the Master Brain, the company's institutional memory. The Master Brain holds what the company knows, and the Book holds how it decides with that knowledge.
Why your AI agents need one
An AI model knows a great deal in general and nothing about your company. Ask it to sort an invoice or reply to a client without giving it your rules, and it will do what an average company would do. Sometimes that matches what you would do. When it does not, nobody finds out until the error reaches the client.
Without a Book of Criteria, three things show up quickly:
- Two agents answer the same situation differently, because each has its own instructions.
- The company's exceptions get lost. The agent treats a client of twenty years and one who arrived yesterday the same way.
- Whoever oversees the agent cannot correct the cause. They fix the case and the error comes back the next week.
With the Book, the agent works from a rule someone wrote and approved. If the rule is wrong, it is changed once and stops failing everywhere.
Documents, instructions and a Book of Criteria: how they differ
The three are often confused, and each does a different job:
| Company documents | An assistant's instructions | Book of Criteria | |
|---|---|---|---|
| What it contains | Procedures, manuals and materials | A text someone wrote for that assistant | Decision rules, one by one |
| What it answers | What something is or how it works | How that assistant should behave | What the company does in each case and why |
| Who reviews it | It is stored and consulted | Whoever set it up, if they remember | A person approves each rule |
| How it changes | Documents are added | It is edited without leaving a record | A new version is activated with a note |
| What the company sees | The document | Almost nothing | Each rule, its source and its version |
The middle column is the most common and the most fragile. Rules hidden in an assistant's instructions work for as long as their author stays with the company and remembers what they wrote.
What a rule looks like
A rule in the Book says when it applies, what is done, why, and where it comes from. An example from an accountancy practice, made up for this article:
- Code: ADM-04.
- Logic: if an invoice arrives without a tax number, it is not sorted. It is set aside and requested from the client.
- Reason: an invoice without a tax number cannot be recorded, and finding that out at quarter end means redoing the work.
- Source: the head of administration, from the cases returned last quarter.
The reason and the source look like decoration, and they are what lets you review the rule a year later, when whoever wrote it no longer remembers. The parts of a rule, with a full example for a professional, are explained on the Digital Twin blog: what a Book of Criteria is, and why every rule has a source.
How a rule gets in and how it changes
A rule goes through four steps, and the agent decides at none of them:
- Someone proposes it, nearly always the person who does that work today.
- It enters the Book as a rule to be reviewed.
- A person with authority over the process reviews it and approves it.
- The Book is activated in a new version, with a note saying what has changed.
When a rule changes, it changes for every agent at once. Because the Book has versions, you can see what it said at any point. The Book in force can be exported whole, in a text format that opens in any editor.
What agents do with the Book
On the Legacy plan of the Legathum platform, agents work on top of the Master Brain: they cite the source of each answer and say they do not know when they do not know. Every question and every answer leaves an audit trail.
That changes the job of whoever oversees them. They no longer review a loose answer: they see which rule was applied and can decide whether the fault lies in the case or in the rule. For high-risk systems, the EU AI Act requires that the people overseeing a system can understand its capacities and limitations (Article 14). With the rules in view, that is much easier to meet.
Who writes it and who answers for it
The people who do the work write it, and the owner of each process approves it. A Book drafted by one person in an office tends to describe how the company ought to work, not how it does.
Three things are worth settling from the start: who can propose a rule, who approves it in each area and how often the whole Book is reviewed.
Having the rules written down also helps with staff. If you employ people in Spain, Article 64.4.d of the Workers' Statute gives the works council the right to be informed of the parameters, rules and instructions behind the algorithms or AI systems that affect working conditions. A company with a Book of Criteria has that information in order. Other jurisdictions have their own rules.
Where to start
With one process and its first ten rules. The method for drawing them out, case by case, is in how to document your company's decision rules before automating them.
In the Legathum AI-First Hybridisation Method, the judgement behind each process is written down before any agent is built, and that work is part of the AI-First hybridisation consultancy. An AI-first company is, among other things, a company whose judgement is written down.
Frequently asked questions
What is a Book of Criteria?
The document where a company writes down its decision rules in plain language, with versions, and where each rule only counts once a person has approved it.
Why does an AI agent need one?
Because an AI model does not know your company's judgement. Without written rules it answers with what seems plausible, and with the Book it works from what the company has decided.
Is it not enough to put the instructions in the assistant?
It works with one assistant and one person. As soon as there are several agents, the instructions drift apart, nobody reviews them and the company cannot see what judgement is being applied.
Who writes the Book of Criteria?
Whoever does the work today proposes the rules and the owner of each process approves them. The agent neither writes nor changes rules.
How many rules do you need to begin?
Those of a single process. With ten well-written rules, an agent can take on the repetitive part and set aside whatever is not covered.
Where do I start?
Choose a process that repeats and ask the person who does it how they decide. If you want to look at it with your own company's case, the first step is a 15-minute meeting with Deibson Silva.