A guide to planning clinical trials that measure repeated events, such as hospital visits, using negative binomial statistics in the gsDesignNB R package.

Use it for negative binomial sample-size calculations, group sequential trial designs, and simulations involving recurrent events or overdispersed counts.

It helps calculate how many participants are needed and test whether a trial design is likely to work when event counts vary more than usual.

gsDesignNB — Skill for Codex by keaven/gsDesignSkills

Install

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.

Any agent

npx skills add keaven/gsDesignSkills --skill gsdesignnb

Clone the repo

git clone --depth 1 https://github.com/keaven/gsDesignSkills

Made for: Codex.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/keaven/gsdesignskills/gsdesignnb/github.svg)](https://agentmods.dev/skills/keaven/gsdesignskills/gsdesignnb)

Your own site

<a href="https://agentmods.dev/skills/keaven/gsdesignskills/gsdesignnb"><img src="https://agentmods.dev/badge/skills/keaven/gsdesignskills/gsdesignnb/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/keaven/gsdesignskills/gsdesignnb"><img src="https://agentmods.dev/badge/skills/keaven/gsdesignskills/gsdesignnb.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 107 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,134 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin unknown No closer match found in the catalogue.

Token cost

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	$0.00107	$0.01134
Opus 5.5	$0.00043	$0.00454
Sonnet 5.5	$0.00021	$0.00227
Haiku 4.5	$0.00011	$0.00113

Measured 2mo ago against content hash 6ce3ff45763b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

gsDesignNB 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 2mo 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.

.agents/skills/gsDesignNB/SKILL.md · 83 lines

The source is not reproduced here

No licence file

Read it on GitHub

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

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.

2mo ago First seen · 83 lines · 107 tokens per session scan A 6ce3ff45763b

Subscribe to this mod's changes

gsDesignNB is a skill published in the GitHub repository keaven/gsDesignSkills (7 stars, last pushed 3mo ago), with no licence file. It adds 107 tokens to every session and 1,134 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-08-31.

Planning Scientific

gsDesignNB next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
gsDesignNBkeaven/gsDesignSkills	Skill	7	3mo ago	none	A	107	Codex
instrument-data-to-allotropeanthropics/knowledge-work-plugins	Skill	35k	2d ago	Apache-2.0	A	123	Claude Code
exploratory-data-analysisK-Dense-AI/scientific-agent-skills	Skill	56k	4d ago	MIT	A	83	Claude Code
matlabK-Dense-AI/scientific-agent-skills	Skill	56k	4d ago	MIT	A	44	Claude Code
phylogeneticsK-Dense-AI/scientific-agent-skills	Skill	56k	4d ago	MIT	A	71	Claude Code, Codex
research-engineerdavila7/claude-code-templates	Skill	33k	yesterday	MIT	A	43	Claude Code, Codex
mapping-to-snomedmaziyarpanahi/openmed	Skill	5.8k	yesterday	Apache-2.0	A	205	Claude Code