Posting to Slack

Nothing reaches Slack unless a person approved that exact content. Preparing writes a local draft and returns a preview with an approval id; nothing is posted at that point. What counts as the person's approval is the workspace's send policy, and it is not yours to choose or to give. On a read workspace none of this applies: the token cannot post at all, and Slack enforces that rather than this code.

agent-slack draft create --workspace acme/slack --channel C024BE7LR --text 'ready when you are'
agent-slack post prepare --workspace acme/slack --draft <draftId>   # prints the preview, posts nothing
agent-slack post send --workspace acme/slack --draft <draftId> --approval <approvalId> --expect-channel C024BE7LR

With the MCP server connected, slack_post_prepare does the first two steps in one call and returns the same preview, and slack_post_send is the third. Both surfaces run one operation, so they refuse the same things.