Slack Messaging

What This Skill Does

This skill provides guidance on composing effective Slack messages using proper formatting and structure. It's designed to help users write clear, concise, and easily readable messages in Slack. It emphasizes the use of mrkdwn and best practices for message layout.

When to Use

• Drafting a Slack message.
• Formatting a Slack announcement.
• Creating a Slack Canvas.
• Improving message clarity.
• Avoiding common formatting errors.

Key Features

• Provides a mrkdwn syntax guide.
• Highlights common formatting mistakes.
• Offers message structure guidelines.
• Emphasizes brevity and clarity.
• Suggests using line breaks and bullet points.

Manual Installation

Manual installation## When to Use

Apply this skill whenever composing, drafting, or helping the user write a Slack message — including when using slack_send_message, slack_send_message_draft, or slack_create_canvas.

Slack Formatting (mrkdwn)

Slack uses its own markup syntax called mrkdwn, which differs from standard Markdown. Always use mrkdwn when composing Slack messages:

Common Mistakes to Avoid

Do NOT use bold (double asterisks) — Slack uses bold (single asterisks)

• Do NOT use ## headers — Slack does not support Markdown headers.
• Use bold text on its own line instead. Do NOT use text for links — Slack uses format Do NOT use --- for horizontal rules — Slack does not render these

Message Structure Guidelines

• Lead with the point.
• Put the most important information in the first line.
• Many people read Slack on mobile or in notifications where only the first line shows. Keep it short. Aim for 1-3 short paragraphs. If the message is long, consider using a Canvas instead.
• Use line breaks generously.
• Walls of text are hard to read.
• Separate distinct thoughts with blank lines. Use bullet points for lists. Anything with 3+ items should be a list, not a run-on sentence. Bold key information. Use bold for names, dates, deadlines, and action items so they stand out when scanning.

Thread vs. Channel Etiquette

Reply in threads when responding to a specific message to keep the main channel clean. Use reply_broadcast (also post to channel) only when the reply contains information everyone needs to see. Post in the channel (not a thread) when starting a new topic, making an announcement, or asking a question to the whole group. Don't start a new thread to continue an existing conversation — find and reply to the original message.

Tone and Audience

Match the tone to the channel — #general is usually more formal than #random`. Use emoji reactions instead of reply messages for simple acknowledgments (though note: the MCP tools can't add reactions, so suggest the user do this manually if appropriate). When writing announcements, use a clear structure: context, key info, call to action. Slack Messaging Best Practices

This skill provides guidance for composing well-formatted, effective Slack messages.

Apply this skill whenever composing, drafting, or helping the user write a Slack message — including when using slack_send_message, slack_send_message_draft, or slack_create_canvas.

Slack uses its own markup syntax called mrkdwn, which differs from standard Markdown. Always use mrkdwn when composing Slack messages:

Do NOT use bold (double asterisks) — Slack uses bold (single asterisks)

• Do NOT use ## headers — Slack does not support Markdown headers.

• Use bold text on its own line instead. Do NOT use text for links — Slack uses format Do NOT use --- for horizontal rules — Slack does not render these

• Lead with the point.

• Put the most important information in the first line.

• Many people read Slack on mobile or in notifications where only the first line shows. Keep it short. Aim for 1-3 short paragraphs. If the message is long, consider using a Canvas instead.

• Use line breaks generously.

• Walls of text are hard to read.

• Separate distinct thoughts with blank lines. Use bullet points for lists. Anything with 3+ items should be a list, not a run-on sentence. Bold key information. Use bold for names, dates, deadlines, and action items so they stand out when scanning.

Reply in threads when responding to a specific message to keep the main channel clean. Use reply_broadcast (also post to channel) only when the reply contains information everyone needs to see. Post in the channel (not a thread) when starting a new topic, making an announcement, or asking a question to the whole group. Don't start a new thread to continue an existing conversation — find and reply to the original message.

Match the tone to the channel — #general is usually more formal than #random`. Use emoji reactions instead of reply messages for simple acknowledgments (though note: the MCP tools can't add reactions, so suggest the user do this manually if appropriate). When writing announcements, use a clear structure: context, key info, call to action.