slack-messaging

Slack Messaging Best Practices

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

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_schedule_message. The formatting rules below cover these message tools. slack_create_canvas uses a different, richer markdown dialect — see the Canvas note below.

Formatting

The message tools (slack_send_message, slack_send_message_draft, slack_schedule_message) accept standard markdown and convert it to Slack formatting on send. Write normal markdown. Do not use Slack's legacy mrkdwn syntax (*bold*, ~strike~); those single-character forms mean something different in standard markdown. Each text element is limited to ~5000 characters.

Format	Syntax
Bold	**text**
Italic	_text_ (or *text*)
Strikethrough	~~text~~
Code (inline)	`code`
Quote	> text
Link	[display text](url)
Bulleted list	- item
Numbered list	1. item

Block elements also work. Write them as literal markdown:

• Code block with an optional language for syntax highlighting:

  ```python
  print("hello")
  ```
  

• Table with | delimiters (escape a literal pipe inside a cell as \|):

  | Feature | Status |
  |---------|--------|
  | Tables  | works  |
  

• Headers with # / ## / ###:

  ## Section title
  

The one thing that does not embed in a message: inline images (![alt](url)) typically render as a plain link rather than an inline image. For rich embedded layouts (buttons, images, structured cards) you need Block Kit; for a document-style surface where images do embed, use a canvas. See the Notes below.