pins_add · Slack MCP: Risk & Policy

WHAT IT DOES

What pins_add does on Slack

AI agents use pins_add 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 pins_add needs a policy

Pinning is a reversible write operation that modifies channel organization and visibility without deleting or executing arbitrary code. While it affects shared channel state and could be misused to spam or mislead users, it is not destructive (pins can be removed) and does not execute code or move money.

From the tool's definition Tool name 'pins_add' and description 'Pin an item to a channel' indicate the tool creates a new pin association, which modifies channel state by adding metadata to an item.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

pins_add Rate-limited

pins_add 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": {
    "pins_add": {
      "limits": [
        {
          "counter": "pins_add_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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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 pins_add

What does the pins_add tool do? +

Pin an item to a channel. 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 pins_add? +

Register the Slack MCP server in PolicyLayer and add a rule for pins_add: 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 pins_add? +

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

Can I rate-limit pins_add? +

Yes. Add a rate_limit block to the pins_add 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 pins_add completely? +

Set action: deny in the PolicyLayer policy for pins_add. 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 pins_add? +

pins_add 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.