Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add human-avatar/skills-for-humanity --skill s4h-ecology-keystone-speciesgit clone --depth 1 https://github.com/human-avatar/skills-for-humanityWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/human-avatar/skills-for-humanity/s4h-ecology-keystone-species)<a href="https://agentmods.dev/skills/human-avatar/skills-for-humanity/s4h-ecology-keystone-species"><img src="https://agentmods.dev/badge/skills/human-avatar/skills-for-humanity/s4h-ecology-keystone-species/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/human-avatar/skills-for-humanity/s4h-ecology-keystone-species"><img src="https://agentmods.dev/badge/skills/human-avatar/skills-for-humanity/s4h-ecology-keystone-species.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00068 | $0.01812 |
| Opus 5 | $0.00034 | $0.00906 |
| Sonnet 5 | $0.00014 | $0.00362 |
| Haiku 4.5 | $0.00007 | $0.00181 |
Grade A, and why
s4h-ecology-keystone-species scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 118 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Ecology: Keystone Species
In 1966, ecologist Robert Paine removed a single predator — the ochre sea star (Pisaster ochraceus) — from an intertidal zone on the coast of Washington state. Within months, mussel populations exploded, crowding out barnacles, algae, and limpets. A system that had held twelve species collapsed to near-monoculture. Paine coined the term "keystone species" for organisms whose influence on the ecosystem is disproportionate to their biomass or abundance. Remove the keystone and the arch falls.
The same structural logic applies in human systems. Every organisation, market, platform, or community has entities — people, roles, institutions, technologies, or relationships — whose contribution to system structure far exceeds their apparent size or weight. They are often not the largest or loudest actors. They are the connectors, the maintainers, the trust nodes, the bridges between otherwise disconnected clusters. When they leave, retire, burn out, or are restructured away, the system does not simply shrink — it reorganises, often badly.
Keystone species analysis is not the same as identifying your most valuable people or assets. Value and structural indispensability are different properties. A top performer can be replaced by another top performer. A keystone cannot be replaced by a substitute — their structural position is what matters, and that position is a function of relationships, trust, and accumulated context that cannot be quickly transferred.
Your Process
Step 1: Scope the System Define the system being analysed — its components, boundaries, and the type of structure you're mapping (an organisation, a supply chain, an ecosystem of partners, a technology stack, a community). The keystone analysis depends entirely on what structural relationships matter in this context.
Framing check: Confirm the system and the structural question in focus before continuing. State what you've identified in one sentence, then use AskUserQuestion:
- Question: "I'm reading this as: [your one-sentence framing of the system and what structural relationships matter]. Is that right?"
- Header: "Framing"
- Options:
- Yes — proceed — framing is correct
- Adjust — one element is off; user will correct it before you continue
- Reframe — different situation than read; incorporate the correction before proceeding
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 12d ago First seen · 118 lines · 68 tokens per session scan A decb08da4bc1
s4h-ecology-keystone-species is a skill published in the GitHub repository human-avatar/skills-for-humanity (223 stars, last pushed 1mo ago), licensed MIT. It adds 68 tokens to every session and 1,812 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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