Slack Mcp Server New Tools Developer Guide 2026

Date: 2026-06-01
Track: tool-scout
Slug: slack-mcp-server-new-tools-developer-guide-2026
Environment: Source-based inspection — no Slack API key

New Tools Verified (May 13, 2026)

Source: docs.slack.dev/changelog/2026/05/13/new-mcp-tools/

add_reaction — adds emoji reaction to a Slack message on behalf of authenticated user
create_conversation — creates new Slack channel, group DM, or IM conversation
list_channel_members — retrieves user IDs for members of a given channel or conversation
list_emoji — returns list of custom emoji available in the workspace
read_files — retrieves metadata and content of files shared in Slack workspaces

Original MCP Tools (from Feb 17, 2026 GA launch)

Source: docs.slack.dev/changelog/2026/02/17/slack-mcp/

search_messages — search Slack workspace messages with filters
post_message — post messages to channels or DMs
read_channel — retrieve channel messages and metadata
list_users — list workspace users
list_channels — list workspace channels
get_user_info — retrieve user details
canvas operations — read/write Slack canvases
Real-time Search (RTS) API — structured semantic search

Growth Metrics Verified

25x increase in RTS queries and MCP tool calls (source: Slack blog powering-agentic-collaboration)
30 new Salesforce AI features in May 2026 wave (source: chatforest.com salesforce-slack-mcp)

Security Model Confirmed

Only Marketplace-published apps and internal apps can use MCP (unlisted apps prohibited)
Workspace admins approve and manage all MCP client integrations
Tokens scoped per user (agent acts on behalf of authenticated user)

Not Tested

No Slack workspace API calls (no API key available)
No agent execution tested
No rate limit or quota behavior verified

Sources