# slack_list_channels

List public or pre-defined channels in the workspace with pagination

Agent View of the PolicyLayer registry record for `slack_list_channels`. HTML page: https://policylayer.com/tools/slack/slack-list-channels

## Facts

- Tool: `slack_list_channels`
- Server: Slack (`@modelcontextprotocol/server-slack`) — https://policylayer.com/tools/slack.md
- Install: `npx -y @modelcontextprotocol/server-slack`
- Homepage: https://github.com/modelcontextprotocol/server-slack
- Risk category: Read (Low risk)
- Registry record: grade F, identity verified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "slack_list_channels",
    "arguments": {}
  }
}
```

## Why slack_list_channels is rated Low

This tool performs a read-only query of channel data with pagination. It retrieves information about channels but does not create, modify, delete, or execute any operations. The act of listing pre-existing public channels has no side effects and poses minimal security risk even if misused by an agent.

From the tool's own definition: "Tool name 'slack_list_channels' and description 'List public or pre-defined channels in the workspace with pagination' indicate a query operation that retrieves channel metadata without modification."

## Use case

AI agents call slack_list_channels to retrieve information from Slack without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Slack:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "slack_list_channels": {}
  }
}
```

## Other tools on Slack (7)

- `slack_get_channel_history` — Read — https://policylayer.com/tools/slack/slack-get-channel-history.md
- `slack_get_thread_replies` — Read — https://policylayer.com/tools/slack/slack-get-thread-replies.md
- `slack_get_user_profile` — Read — https://policylayer.com/tools/slack/slack-get-user-profile.md
- `slack_get_users` — Read — https://policylayer.com/tools/slack/slack-get-users.md
- `slack_add_reaction` — Write — https://policylayer.com/tools/slack/slack-add-reaction.md
- `slack_post_message` — Write — https://policylayer.com/tools/slack/slack-post-message.md
- `slack_reply_to_thread` — Write — https://policylayer.com/tools/slack/slack-reply-to-thread.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=slack · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/slack