views_update · Slack MCP: Risk & Policy

WHAT IT DOES

What views_update does on Slack

AI agents use views_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 views_update needs a policy

The 'views_update' tool modifies Slack views—likely modals, home tabs, or canvas content—which are data structures that can be changed but not irreversibly deleted. This is a Write operation. Severity is high because an agent could modify views to phish users, inject misleading content, or disrupt workspace UX at scale across channels or users. The broad access model described ('full access to Slack') amplifies risk.

From the tool's definition Tool name 'views_update' combined with server description stating 'full access to Slack: messages, channels, files, canvases, lists' indicates modification of Slack UI views/canvases. The 'update' operation is reversible (Write category).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

views_update Rate-limited

views_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": {
    "views_update": {
      "limits": [
        {
          "counter": "views_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 views_update

What does the views_update tool do? +

views_update. 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 views_update? +

Register the Slack MCP server in PolicyLayer and add a rule for views_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 views_update? +

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

Can I rate-limit views_update? +

Yes. Add a rate_limit block to the views_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 views_update completely? +

Set action: deny in the PolicyLayer policy for views_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 views_update? +

views_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.