create_mr_discussion · Mcp Gitlab MCP: Risk & Policy

WHAT IT DOES

What create_mr_discussion does on Mcp Gitlab

AI agents use create_mr_discussion to create or update resources in Mcp Gitlab — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mcp Gitlab environment.

WHY IT NEEDS A POLICY

Why create_mr_discussion needs a policy

The tool creates new data (a discussion/comment) in GitLab's merge request system. This is a Write operation because it modifies state reversibly—comments are not destructive, do not execute code or commands, and do not move money. The blast radius is low because code-review comments are collaborative, non-destructive additions that do not alter the actual codebase or pipeline execution.

From the tool's definition Tool name 'create_mr_discussion' and description 'Create a code-review comment on a specific line in an MR' indicate creation of a new comment/discussion object. This is a reversible write operation (comments can be edited or deleted).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_mr_discussion Rate-limited

create_mr_discussion 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": {
    "create_mr_discussion": {
      "limits": [
        {
          "counter": "create_mr_discussion_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 Mcp Gitlab, so you can run agents against it safely.

FAQ

Questions about create_mr_discussion

What does the create_mr_discussion tool do? +

Create a code-review comment on a specific line in an MR. It is categorised as a Write tool in the Mcp Gitlab MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_mr_discussion? +

Register the Mcp Gitlab MCP server in PolicyLayer and add a rule for create_mr_discussion: 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 Mcp Gitlab. Nothing to install.

What risk level is create_mr_discussion? +

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

Can I rate-limit create_mr_discussion? +

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

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

create_mr_discussion is provided by the Mcp Gitlab MCP server (wanadev/gitlab-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.