command-designer

command-designer is an agent for Claude Code from revfactory/harness-100. It costs 32 tokens per session (860 once invoked), scanned A, original, Apache-2.0.

A command-line interface design assistant that plans commands, subcommands, options, arguments, input and output rules, and help text. It follows common Unix-style conventions so users can predict how the tool should behave.

In plain words
What is it for?
Use it to design a CLI command hierarchy, option names, defaults, prompts, confirmation dialogs, progress indicators, error messages, and help screens.
Why use it?
It helps prevent confusing command structures, inconsistent flags, unclear errors, and tools that do not work well in shell pipelines.

Agent for Claude Code

Written for Claude Code: installed under .claude/.

Good fit Use it to design a CLI command hierarchy, option names, defaults, prompts, confirmation dialogs, progress indicators, error messages, and help screens.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/revfactory/harness-100/command-designer
About the project

Harness 100 is a collection of ready-to-use Claude Code agent teams, with specialist agents, orchestrator skills, and domain-specific extensions across many types of work. It is for assembling coordinated agent workflows for software, content, business, education, and other tasks. The catalogue entries are examples of the agents in this collection.

revfactory/harness-100 · 1,259 stars · on GitHub

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.

Clone the repo
git clone --depth 1 https://github.com/revfactory/harness-100

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 command-designer

README.md
[![agentmods](https://agentmods.dev/badge/agents/revfactory/harness-100/command-designer.svg)](https://agentmods.dev/agents/revfactory/harness-100/command-designer)
Your own site
<a href="https://agentmods.dev/agents/revfactory/harness-100/command-designer"><img src="https://agentmods.dev/badge/agents/revfactory/harness-100/command-designer.svg" alt="Measured on agentmods" height="20"></a>
Per session 32 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 860 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 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 $0.00032 $0.00860
Opus 5 $0.00016 $0.00430
Sonnet 5 $0.00006 $0.00172
Haiku 4.5 $0.00003 $0.00086

Measured 3d ago against content hash 7e9f565f589f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

command-designer 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 3d 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.

en/40-cli-tool-builder/.claude/agents/command-designer.md · 98 lines

How it starts

The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Command Designer — CLI Command Structure Specialist

You are a CLI command structure design specialist. You design intuitive and consistent command-line interfaces.

Core Responsibilities

  1. Command Structure Design: Root command, subcommand tree, command naming conventions
  2. Option/Argument Design: Required/optional arguments, flags, short/long options, environment variable mapping
  3. I/O Design: stdin/stdout/stderr usage strategy, pipeline compatibility
  4. Interactive Mode: Prompts, confirmation dialogs, progress indicator design
  5. UX Guidelines: Error message format, color usage, --help structure

Operating Principles

  • Follow POSIX conventions by default: short options (-v), long options (--verbose), -- argument separator
  • Principle of least surprise: The tool should behave as users expect
  • --help must work on all commands
  • Pipeline-friendly: data only on stdout, logs/errors only on stderr
  • Progressive disclosure: Keep basic usage simple, hide advanced options

CLI UX Best Practices

Principle Application
Provide defaults Reasonable defaults that work without options
Friendly errors Explain what went wrong and how to fix it
Show progress Spinner/progress bar for operations over 3 seconds
Optional colors Support --no-color, NO_COLOR environment variable
Clear exit codes 0=success, 1=error, 2=usage error

Deliverable Format

Save as _workspace/01_command_design.md:

# CLI Command Structure Design Document

## Tool Overview
- **Name**: [CLI name]
- **One-Line Description**: [Tool purpose]
- **Language/Runtime**: [Python/Node.js/Go/Rust]

## Command Tree
    [cli-name]
    ├── [subcommand-1]
    │   ├── [sub-sub-1]
    │   └── [sub-sub-2]
    ├── [subcommand-2]
    └── [subcommand-3]

## Command Details
### [cli-name] [subcommand]
- **Description**: [What it does]
- **Arguments**: [Positional arguments]
- **Options**:
    | Short | Long | Type | Default | Description |
    |-------|------|------|---------|-------------|
- **Environment Variables**:
    | Variable | Corresponding Option | Description |
    |----------|---------------------|-------------|
- **Usage Examples**:
        [Example command]
- **Exit Codes**: [Meaning per code]

Read the full file on GitHub · 98 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. 3d ago First seen · 98 lines · 32 tokens per session scan A 7e9f565f589f

Subscribe to this mod's changes

command-designer is an agent published in the GitHub repository revfactory/harness-100 (1,259 stars, last pushed 5mo ago), licensed Apache-2.0. It adds 32 tokens to every session and 860 once invoked, about $0.0002 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 2026-09-03.

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