cli-tool-design

cli-tool-design is a skill for Claude Code from organvm-iv-taxis/a-i--skills. It costs 54 tokens per session (1,660 once invoked), scanned A, original, Apache-2.0.

Guidance for designing command-line programs, which are tools operated by typing commands in a terminal.

In plain words
What is it for?
Use it to plan subcommands, arguments, help text, terminal output, exit behavior, and shell completion with tools such as Click, Typer, argparse, Rust clap, or Go cobra.
Why use it?
It helps make commands easy to discover, combine, and understand, with consistent options, output, and error codes.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the example-skills plugin — 47 skills, 2 commands, 1 agent shipped together

Good fit Use it to plan subcommands, arguments, help text, terminal output, exit behavior, and shell completion with tools such as Click, Typer, argparse, Rust clap, or Go cobra.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/organvm-iv-taxis/a-i--skills/cli-tool-design
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 organvm-iv-taxis/a-i--skills --skill cli-tool-design
Clone the repo
git clone --depth 1 https://github.com/organvm-iv-taxis/a-i--skills

Made for: Claude Code.

Or install example-skills, the plugin that ships this one along with the rest of its 47 skills, 2 commands, 1 agent.

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 cli-tool-design

README.md
[![agentmods](https://agentmods.dev/badge/skills/organvm-iv-taxis/a-i--skills/cli-tool-design/github.svg)](https://agentmods.dev/skills/organvm-iv-taxis/a-i--skills/cli-tool-design)
Your own site
<a href="https://agentmods.dev/skills/organvm-iv-taxis/a-i--skills/cli-tool-design"><img src="https://agentmods.dev/badge/skills/organvm-iv-taxis/a-i--skills/cli-tool-design/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 cli-tool-design

Your own site · 80×15
<a href="https://agentmods.dev/skills/organvm-iv-taxis/a-i--skills/cli-tool-design"><img src="https://agentmods.dev/badge/skills/organvm-iv-taxis/a-i--skills/cli-tool-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,660 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
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Excessive Agency · line 122
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 $0.00054 $0.01660
Opus 5 $0.00027 $0.00830
Sonnet 5 $0.00011 $0.00332
Haiku 4.5 $0.00005 $0.00166

Measured 12d ago against content hash a37cea783f6c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

cli-tool-design 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.

distributions/claude/skills/cli-tool-design/SKILL.md · 262 lines

How it starts

The opening of the file, as written. The whole thing — 262 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLI Tool Design

Build command-line tools that are discoverable, composable, and pleasant to use.

Design Principles

The UNIX Philosophy Applied

  1. Do one thing well — Each command has a clear, singular purpose
  2. Compose through pipes — Support stdin/stdout for chaining
  3. Fail loudly — Non-zero exit codes and stderr for errors
  4. Be predictable — Consistent flags, consistent output format

Command Structure

program [global-options] command [command-options] [arguments]

Example:

organvm --verbose registry update --organ IV a-i--skills

Framework Selection

Framework Language Best For
Typer Python Modern CLIs with type hints, auto-completion
Click Python Complex CLIs, plugins, nested groups
argparse Python Zero-dependency, stdlib-only
clap Rust High-performance, compiled CLIs
cobra Go Go microservice CLIs

Basic Command

import typer

app = typer.Typer(help="ORGANVM system management CLI")

@app.command()
def status(
    organ: str = typer.Argument(help="Organ number (I-VII or META)"),
    verbose: bool = typer.Option(False, "--verbose", "-v", help="Show detailed output"),
):
    """Show the status of an organ's repositories."""
    # Implementation here

Subcommand Groups

app = typer.Typer()
registry_app = typer.Typer(help="Registry operations")
app.add_typer(registry_app, name="registry")

@registry_app.command("update")
def registry_update(
    organ: str = typer.Argument(help="Target organ"),
    dry_run: bool = typer.Option(False, "--dry-run", "-n"),
):
    """Update registry entries for an organ."""

Rich Output Integration

from rich.console import Console
from rich.table import Table

console = Console(stderr=True)  # Status to stderr

def show_repos(repos: list[dict]):
    table = Table(title="Repositories")
    table.add_column("Name", style="cyan")
    table.add_column("Status", style="green")
    table.add_column("Tier")
    for repo in repos:
        table.add_row(repo["name"], repo["status"], repo["tier"])
    console.print(table)

Read the full file on GitHub · 262 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. 12d ago First seen · 262 lines · 54 tokens per session scan A a37cea783f6c

Subscribe to this mod's changes

cli-tool-design is a skill published in the GitHub repository organvm-iv-taxis/a-i--skills (17 stars, last pushed 16d ago), licensed Apache-2.0. It adds 54 tokens to every session and 1,660 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.