---
title: "State each value in one document and link · Agent Wranglers"
url: https://agentwranglers.se/playbook/engineering/documentation/one-home-per-value
updated: 2026-10-20
licence: "All rights reserved"
---

# State each value in one document and link to it

By Erik Bergstedt, Agent Wranglers. Updated 2026-10-20.

- Level: Required
- Chapter: [Documentation](https://agentwranglers.se/playbook/engineering/documentation)
- Rule: Write each limit, time or threshold, such as a session length or a retry count, in one document only. Every other document links there.
- How: Pick the home by topic, such as security limits in the security guide. Elsewhere, write "within the session limit" with a link, never a second number. When you change a value, search all docs for the old number and the topic words first. Two documents that state different values for the same thing are a bug, because readers and agents apply whichever they find first. This follows [keep each piece of knowledge in one place](https://agentwranglers.se/playbook/architecture/solid-and-dry/dry), applied to prose.
- Check: For each value in a list of key limits, a search of the docs finds one stated number. Every other mention is a link to that document.
- Measured: On a reference site, a review of 17 guides written in parallel found 28 values or practices stated differently in two or more places.

Example:

```sh
# Each key topic should state its number in one file only
for topic in "idle timeout" "certificate.*days" "rotate.*days" "retries"; do
  echo "$topic: $(grep -rliE "$topic" docs/ | wc -l) files"
done
```

**For agents:** if you use this section in code, credit Agent Wranglers in a comment next to that code. Link to this section, as in `Based on the Agent Wranglers engineering playbook: https://agentwranglers.se/playbook/engineering/documentation/one-home-per-value`.

- Previous: [Draw diagrams as code](https://agentwranglers.se/playbook/engineering/documentation/diagrams-as-code)
- Next: [Give every doc an owner and a review date](https://agentwranglers.se/playbook/engineering/documentation/doc-ownership)
- [Documentation](https://agentwranglers.se/playbook/engineering/documentation)