dunbars-number SKILL.md skillA
dunbars-number from deciqai/knowledge-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add deciqai/knowledge-skills/dunbars-number@git:20261025.cb4e537Pins git:20261025.cb4e537 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- deciqai/knowledge-skills
- Path
dunbars-number/SKILL.md- Versions recorded
- 5
- Latest version
- git:20261025.cb4e537, committed Oct 25, 2026
- First version recorded
- Jul 16, 2026
- Size
- 8,204 bytes
- Repository stars
- 13
- License
- MIT
Activate when: team headcount is approaching or crossing 150 (or 50, or 500); someone says "coordination is getting harder," "we lost the startup feel," or "we don't know who does what anymore"; deciding whether to split a team, open a new office, or add a management layer. Do NOT activate when: group is well below 50 and problems are clearly interpersonal; core issue is incentive misalignment rather than group size (use principal-agent instead). More: deciqai.com/s/dunbars-number.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Dunbar's Number ## Overview **Dunbar's number** (~150) is the cognitive limit on stable social groups the human neocortex can sustain, with nested layers at ~5, ~15, ~50, then outer bands at ~500 and ~1,500. Derived by Robin Dunbar (1992) from primate neocortex ratios. Key implication: **below ~150, informal trust coordinates behavior; above ~150, formal hierarchy becomes architecturally mandatory** — not a cultural choice. Composes with [`network-effects`](../network-effects/SKILL.md) (different coordination mechanisms below vs. above 150), [`principal-agent`](../principal-agent/SKILL.md) (exceeding 150 multiplies agency problems informal trust can no longer cover), [`founder-mindset`](../founder-mindset/SKILL.md) (founder relationship bandwidth peaks at ~150 — first breakpoint demanding shift from doing to delegating structure). ## When to Use - Headcount approaching or crossing 150 (or 50, or 500) - "Coordination getting harder" complaints with no obvious structural cause - Deciding to split a team, open a new office, or create a sub-unit - Designing org structure for a scaling startup; evaluating acquisition integration plans …
Read the whole file at its exact version.
How to install
mdr add deciqai/knowledge-skills/dunbars-number@sha256:5bb485c51a029733The line at the top of this page pins the label git:20261025.cb4e537, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_mpk6qkfwioz23w3j)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 5 versions of this file, between Jul 16, 2026 and Oct 25, 2026, about one every 25 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261025.cb4e537 latest | 2026-10-25 | cb4e537 | 8,204 B | A | view · diff |
| git:20260816.be84677 | 2026-08-16 | be84677 | 8,204 B | A | view · diff |
| git:20260719.ed3f856 | 2026-07-19 | ed3f856 | 8,204 B | A | view · diff |
| git:20260717.2ed857e | 2026-07-17 | 2ed857e | 8,204 B | A | view · diff |
| git:20260716.fac12bf | 2026-07-16 | fac12bf | 8,204 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (8204 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
deciqai/knowledge-skills · 13 stars · license MIT · pushed 2026-10-25 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_mpk6qkfwioz23w3j GET https://markdownregistry.com/api/v1/resolve?ref=deciqai/knowledge-skills/dunbars-number GET https://markdownregistry.com/api/v1/blob/5bb485c51a029733dd6b5f7565330401ec4f4a718fe78ac0e6a0594bbb9e6409
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.