Creates and modifies Claude Code slash commands following best practices. Use when user requests creating, updating, modifying, improving, or editing slash commands. Triggers include "create/make/new command", "slash command", "/command-name", file paths with /commands/, "update/modify/improve command X". Handles command structure, YAML frontmatter (description, allowed-tools, argument-hint, model), argument patterns ($ARGUMENTS, $1 $2, @filepath), tool restrictions, discoverability. Delegates to edit-tool orchestrator if uncertain about tool type (command vs skill vs agent vs script).