For anyone writing to American clients or working with US teams. Handles the spelling differences (organize not organise, center not centre), kills corporate buzzwords (no more "synergize" or "circle back"), and keeps you in that professional-but-human tone Americans expect in business writing. The avoid list alone is worth it. Includes a formality ladder for different contexts, from Slack messages to proposals, plus specific guidance on when to use "Best" versus "Thanks" versus "Best regards". Works for emails, proposals, web copy, anything going to an American audience. If you've ever second-guessed whether to write "Hi" or "Dear" or wondered if your tone sounds too stiff, this covers it.
npx skills add https://github.com/jezweb/claude-skills --skill us-business-english