brainstorm-experiments-existing

brainstorm-experiments-existing is a skill for Claude Code from yuusakuri/agent-skills. It costs 48 tokens per session (519 once invoked), scanned A, a copy of brainstorm-experiments-existing, MIT.

A method for testing assumptions about an existing product before committing to a full feature or change.

In plain words
What is it for?
Use it to plan prototype tests, first-click or task-completion tests, fake-door tests, technical spikes, production A/B tests, or behavior-focused surveys.
Why use it?
It helps teams learn what users actually do with less time, cost, and implementation risk.

Skill for Claude Code

Written for Claude Code: $ARGUMENTS substitution.

Good fit Use it to plan prototype tests, first-click or task-completion tests, fake-door tests, technical spikes, production A/B tests, or behavior-focused surveys.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/yuusakuri/agent-skills/brainstorm-experiments-existing
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 yuusakuri/agent-skills --skill brainstorm-experiments-existing
Clone the repo
git clone --depth 1 https://github.com/yuusakuri/agent-skills

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 brainstorm-experiments-existing

README.md
[![agentmods](https://agentmods.dev/badge/skills/yuusakuri/agent-skills/brainstorm-experiments-existing/github.svg)](https://agentmods.dev/skills/yuusakuri/agent-skills/brainstorm-experiments-existing)
Your own site
<a href="https://agentmods.dev/skills/yuusakuri/agent-skills/brainstorm-experiments-existing"><img src="https://agentmods.dev/badge/skills/yuusakuri/agent-skills/brainstorm-experiments-existing/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 brainstorm-experiments-existing

Your own site · 80×15
<a href="https://agentmods.dev/skills/yuusakuri/agent-skills/brainstorm-experiments-existing"><img src="https://agentmods.dev/badge/skills/yuusakuri/agent-skills/brainstorm-experiments-existing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 519 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 100% copy Near-identical to another mod 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 $0.00048 $0.00519
Opus 5.5 $0.00019 $0.00208
Sonnet 5.5 $0.00010 $0.00104
Haiku 4.5 $0.00005 $0.00052

Measured 2mo ago against content hash d72da1f4f08d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

brainstorm-experiments-existing 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

This is a copy

100% identical to brainstorm-experiments-existing — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/brainstorm-experiments-existing/SKILL.md · 52 lines

How it starts

The opening of the file, as written. The whole thing — 52 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Design Experiments (Existing Product)

Design low-effort experiments to test product assumptions before committing to full implementation.

Context

You are helping a product team design experiments for $ARGUMENTS. The team has a feature idea and assumptions that need validation.

If the user provides files (PRDs, assumption lists, designs), read them first.

Instructions

The user will describe their idea and assumptions. Work through these steps:

  1. Clarify the idea and assumptions: Confirm what the team wants to build and what they need to validate.

  2. Suggest experiments for each assumption. Consider methods like:

    • First-click testing or task completion with a prototype
    • Feature stubs or fake door tests
    • Technical spikes
    • A/B tests on production (with risk mitigation)
    • Wizard of Oz approaches
    • Survey-based validation (behavioral, not opinion-based)
  3. Key principles to follow:

    • Measure actual behavior, not users' opinions
    • Test responsibly — don't put users or the business at risk
    • For production tests (e.g., A/B tests), explain risk mitigation strategies
    • Aim for maximum validated learning with minimal effort
  4. For each experiment, specify:

    • Assumption: What do we believe?
    • Experiment: What exactly will we do to validate it?
    • Metric: What will be measured?
    • Success threshold: The expected value if we are right

Think step by step. Present experiments in a clear table or structured format. Save as markdown if substantial.


Further Reading

Read the full file on GitHub · 52 lines

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 · 52 lines · 48 tokens per session scan A d72da1f4f08d

Subscribe to this mod's changes

brainstorm-experiments-existing is a skill published in the GitHub repository yuusakuri/agent-skills (2 stars, last pushed 14d ago), licensed MIT. It adds 48 tokens to every session and 519 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to brainstorm-experiments-existing, differing in 0 lines, and is treated as a copy.

Related

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