experiment-craft

experiment-craft is a skill for Claude Code from EvoScientist/EvoSkills. It costs 172 tokens per session (1,586 once invoked), scanned A, original, Apache-2.0.

A structured method for debugging and improving research experiments that are already running. It records hypotheses, runs, failures, results, and next steps.

In plain words
What is it for?
Use it to investigate failed research code, diagnose methods that underperform on some data, and keep an organized experiment log while iterating.
Why use it?
It helps explain why an experiment gives poor or unexpected results, instead of encouraging random trial and error. This can prevent abandoning a good approach or wasting runs.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it to investigate failed research code, diagnose methods that underperform on some data, and keep an organized experiment log while iterating.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/evoscientist/evoskills/experiment-craft
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 EvoScientist/EvoSkills --skill experiment-craft
Clone the repo
git clone --depth 1 https://github.com/EvoScientist/EvoSkills

Made for: Claude Code.

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.

agentmods badge for experiment-craft

README.md
[![agentmods](https://agentmods.dev/badge/skills/evoscientist/evoskills/experiment-craft/github.svg)](https://agentmods.dev/skills/evoscientist/evoskills/experiment-craft)
Your own site
<a href="https://agentmods.dev/skills/evoscientist/evoskills/experiment-craft"><img src="https://agentmods.dev/badge/skills/evoscientist/evoskills/experiment-craft/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.

agentmods 80×15 button for experiment-craft

Your own site · 80×15
<a href="https://agentmods.dev/skills/evoscientist/evoskills/experiment-craft"><img src="https://agentmods.dev/badge/skills/evoscientist/evoskills/experiment-craft.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 172 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,586 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. Third-party audits
  • Socket pass 18 Mar 2026
  • Snyk pass 17 Mar 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00172 $0.01586
Opus 5.5 $0.00069 $0.00634
Sonnet 5.5 $0.00034 $0.00317
Haiku 4.5 $0.00017 $0.00159

Measured 2mo ago against content hash a56d30cbb5a1, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

experiment-craft 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

skills/experiment-craft/SKILL.md · 131 lines

How it starts

The opening of the file, as written. The whole thing — 131 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Experiment Craft

A systematic approach to running, debugging, and iterating on research experiments. The critical skill is not running more experiments — it's understanding WHY experiments fail.

When to Use This Skill

  • User's experiment is not working or producing unexpected results
  • User needs help diagnosing why a method fails on certain data
  • User wants to organize their experiment process with structured logging
  • User asks about debugging research code or iterating on approaches
  • User mentions "experiment debugging", "why doesn't this work", "experiment log", "results are wrong"

This skill is typically loaded from within experiment-pipeline when a stage attempt fails. After debugging, return to the pipeline's stage-gate structure to continue. Can also be used standalone for any experiment debugging.

The Debugging Mindset

Finding WHY experiments fail is the most critical research skill. Not analyzing results leads to two failure modes:

  1. Slow progress: Running random experiments without understanding failure causes
  2. Wasted time: Abandoning good approaches because activation tricks were missed

The goal is not to run more experiments. The goal is to run the RIGHT experiments — ones that isolate causes and test specific hypotheses.

5-Step Diagnostic Flow

When an experiment fails or produces unexpected results, follow these five steps:

Step 1: Collect Failure Cases

Gather concrete examples of bad results. Look at the actual outputs, not just aggregate metrics. What specifically went wrong? Are the failures systematic or random?

Step 2: Find a Working Version

You need a baseline that works. Two ways to find one:

  • Simplify the task: Reduce data complexity, relax the task setting, add more supervision, use easier inputs
  • Remove your changes: Start from the baseline method and remove your algorithmic improvements one by one

If you can't find any working version, simplify further until something works. There is always a simple enough version that works.

Read the full file on GitHub · 131 lines

Files

What ships with it

2 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.

  1. 2mo ago First seen · 131 lines · 172 tokens per session scan A a56d30cbb5a1

Subscribe to this mod's changes

experiment-craft is a skill published in the GitHub repository EvoScientist/EvoSkills (486 stars, last pushed 10d ago), licensed Apache-2.0. It adds 172 tokens to every session and 1,586 once invoked, about $0.0007 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 2026-08-30.

Related

experiment-craft compared with skills from other repositories

experiment-craft next to 6 skills from other repositories
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experiment-craftEvoScientist/EvoSkillsSkill48610d agoApache-2.0A172Claude Code
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simulation-failure-triageHeshamFS/materials-simulation-skillsSkill8316d agoApache-2.0A141Claude Code
statechartpainhardcore/pstackSkill184d agoMITA70Claude Code, OpenCode
deltasciboheling/deltasciSkill1445mo agoMITA117Claude Code, Codex
bio-genome-assembly-assembly-polishingFridrichMethod/awesome-skillsSkill164d agononeA190Claude Code, Codex
gke-workload-scaling-troubleshootinggoogle/skillsSkill22kyesterdayApache-2.0A170Claude Code, Codex