skills-x: Skill for Claude Code

.claude/skills/brainstorming/SKILL.md

brainstorming is a skill for Claude Code from castle-x/skills-x. It costs 37 tokens per session (1,021 once invoked), scanned A, a copy of brainstorming, MIT.

A guided conversation for turning an idea into an agreed software design before implementation. It examines the project, asks questions, compares approaches, and records the result in a design document.

In plain words
What is it for?
Use it before creating a feature, component, or behavior change, even when the change seems small. It helps produce a reviewed design and implementation plan.
Why use it?
It reduces the risk of building the wrong feature because requirements, constraints, and trade-offs were not clarified first.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is castle-x/skills-x's own configuration. It tells Claude Code how to work on skills-x itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything skills-x configures →

Reuse

Borrowing it

Nothing to install: this file belongs to castle-x/skills-x. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/castle-x/skills-x/main/.claude/skills/brainstorming/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/castle-x/skills-x

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 brainstorming

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/castle-x/skills-x/brainstorming"><img src="https://agentmods.dev/badge/skills/castle-x/skills-x/brainstorming.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 37 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,021 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 $0.00037 $0.01021
Opus 5 $0.00018 $0.00511
Sonnet 5 $0.00007 $0.00204
Haiku 4.5 $0.00004 $0.00102

Measured 9d ago against content hash 7a238df1ebf0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

brainstorming 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 9d 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 brainstorming — 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.

.claude/skills/brainstorming/SKILL.md · 97 lines

How it starts

The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Brainstorming Ideas Into Designs

Overview

Help turn ideas into fully formed designs and specs through natural collaborative dialogue.

Start by understanding the current project context, then ask questions one at a time to refine the idea. Once you understand what you're building, present the design and get user approval.

Anti-Pattern: "This Is Too Simple To Need A Design"

Every project goes through this process. A todo list, a single-function utility, a config change — all of them. "Simple" projects are where unexamined assumptions cause the most wasted work. The design can be short (a few sentences for truly simple projects), but you MUST present it and get approval.

Checklist

You MUST create a task for each of these items and complete them in order:

  1. Explore project context — check files, docs, recent commits
  2. Ask clarifying questions — one at a time, understand purpose/constraints/success criteria
  3. Propose 2-3 approaches — with trade-offs and your recommendation
  4. Present design — in sections scaled to their complexity, get user approval after each section
  5. Write design doc — save to docs/plans/YYYY-MM-DD-<topic>-design.md and commit
  6. Transition to implementation — invoke writing-plans skill to create implementation plan

Process Flow

digraph brainstorming {
    "Explore project context" [shape=box];
    "Ask clarifying questions" [shape=box];
    "Propose 2-3 approaches" [shape=box];
    "Present design sections" [shape=box];
    "User approves design?" [shape=diamond];
    "Write design doc" [shape=box];
    "Invoke writing-plans skill" [shape=doublecircle];

    "Explore project context" -> "Ask clarifying questions";
    "Ask clarifying questions" -> "Propose 2-3 approaches";
    "Propose 2-3 approaches" -> "Present design sections";
    "Present design sections" -> "User approves design?";
    "User approves design?" -> "Present design sections" [label="no, revise"];
    "User approves design?" -> "Write design doc" [label="yes"];
    "Write design doc" -> "Invoke writing-plans skill";
}

Read the full file on GitHub · 97 lines

Files

What ships with it

1 file 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. 9d ago First seen · 97 lines · 37 tokens per session scan A 7a238df1ebf0

Subscribe to this mod's changes

brainstorming is a skill published in the GitHub repository castle-x/skills-x (18 stars, last pushed 4mo ago), licensed MIT. It adds 37 tokens to every session and 1,021 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to brainstorming, differing in 0 lines, and is treated as a copy.

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