# chat_unfurl A write tool on the Slack MCP server. Agent View of the PolicyLayer registry record for `chat_unfurl`. HTML page: https://policylayer.com/tools/karbassi-slack-mcp/chat-unfurl ## Facts - Tool: `chat_unfurl` - Server: Slack (`karbassi/slack-mcp`) — https://policylayer.com/tools/karbassi-slack-mcp.md - Homepage: https://github.com/karbassi/slack-mcp - Risk category: Write (Medium risk) - Registry record: grade F, identity unverified - Server rate-limited: no - Parameters: 0 - Recommended policy verdict: Rate-limited ## Example call (MCP tools/call, JSON-RPC 2.0) ```json { "jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": { "name": "chat_unfurl", "arguments": {} } } ``` ## Why chat_unfurl is rated Medium Based on Slack terminology, 'unfurl' refers to expanding or enriching link previews and message metadata—a write operation that modifies message presentation. While the empty description introduces uncertainty, the tool name and context of a Slack integration strongly indicate it creates or modifies message content/formatting rather than reading, executing code, destroying data, or moving money. From the tool's own definition: "Tool name 'chat_unfurl' suggests modifying how messages or links are displayed/rendered in Slack chat. Unfurling typically involves adding preview metadata or formatting to messages, which is a reversible modification." ## Use case AI agents use chat_unfurl to create or update resources in Slack, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Slack environment. ## Recommended policy (PolicyLayer) Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Slack: ```json { "version": "1", "default": "deny", "tools": { "chat_unfurl": { "limits": [ { "counter": "chat_unfurl_rate", "window": "minute", "max": 30, "scope": "grant" } ] } } } ``` ## Other tools on Slack (232) - `apps_manifest_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/apps-manifest-delete.md - `apps_uninstall` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/apps-uninstall.md - `auth_revoke` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/auth-revoke.md - `bookmarks_remove` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/bookmarks-remove.md - `cache_clear` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/cache-clear.md - `calls_participants_remove` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/calls-participants-remove.md - `canvases_access_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/canvases-access-delete.md - `canvases_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/canvases-delete.md - `channels_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/channels-delete.md - `chat_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/chat-delete.md - `chat_delete_scheduled_message` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/chat-delete-scheduled-message.md - `conversations_kick` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/conversations-kick.md - `drafts_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/drafts-delete.md - `emoji_remove` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/emoji-remove.md - `files_comments_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/files-comments-delete.md - `files_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/files-delete.md - `files_remote_remove` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/files-remote-remove.md - `files_revoke_public_url` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/files-revoke-public-url.md - `pins_remove` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/pins-remove.md - `reactions_remove` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/reactions-remove.md - `reminders_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/reminders-delete.md - `saved_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/saved-delete.md - `slack_lists_access_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/slack-lists-access-delete.md - `slack_lists_items_delete` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/slack-lists-items-delete.md - `slack_lists_items_delete_multiple` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/slack-lists-items-delete-multiple.md - `stars_remove` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/stars-remove.md - `team_external_teams_disconnect` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/team-external-teams-disconnect.md - `users_admin_set_inactive` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/users-admin-set-inactive.md - `users_delete_photo` — Destructive — https://policylayer.com/tools/karbassi-slack-mcp/users-delete-photo.md - `apps_connections_open` — Execute — https://policylayer.com/tools/karbassi-slack-mcp/apps-connections-open.md - …and 202 more: https://policylayer.com/tools/karbassi-slack-mcp.md ## For agents This record is a snapshot. Live verdicts and the full registry: - Check every server in your MCP config at once: `npx -y policylayer stack` - Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md) - Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events` --- Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=karbassi-slack-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/karbassi-slack-mcp