CLI Patterns Skill

When to Activate

• Building a new CLI tool or adding subcommands to an existing one
• Designing the argument interface (flags, options, positional args)
• Implementing --json output, --quiet, or --verbose modes
• Adding interactive prompts or progress indicators
• Writing subprocess-based CLI tests
• Debugging composability issues (piping, stdin, exit codes)

Argument Design

Flags vs. Options vs. Positional Args