slack_lists_items_update · Slack MCP: Risk & Policy

WHAT IT DOES

What slack_lists_items_update does on Slack

AI agents use slack_lists_items_update 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.

WHY IT NEEDS A POLICY

Why slack_lists_items_update needs a policy

This tool updates list item data, which is a reversible write operation. It modifies structured data within Slack lists but does not delete or destroy information. Severity is medium because careless updates could corrupt important shared lists affecting multiple users, but changes are generally reversible through further updates or version history if available.

From the tool's definition Tool name contains 'update' and description states 'Update cells in a list item' — modifying existing list data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

slack_lists_items_update Rate-limited

slack_lists_items_update stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "slack_lists_items_update": {
      "limits": [
        {
          "counter": "slack_lists_items_update_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Slack, so you can run agents against it safely.

FAQ

Questions about slack_lists_items_update

What does the slack_lists_items_update tool do? +

Update cells in a list item. It is categorised as a Write tool in the Slack MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on slack_lists_items_update? +

Register the Slack MCP server in PolicyLayer and add a rule for slack_lists_items_update: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Slack. Nothing to install.

What risk level is slack_lists_items_update? +

slack_lists_items_update is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit slack_lists_items_update? +

Yes. Add a rate_limit block to the slack_lists_items_update rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block slack_lists_items_update completely? +

Set action: deny in the PolicyLayer policy for slack_lists_items_update. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides slack_lists_items_update? +

slack_lists_items_update is provided by the Slack MCP server (karbassi/slack-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.