pr_merge · Pr Review MCP: Risk & Policy

WHAT IT DOES

What pr_merge does on Pr Review

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

WHY IT NEEDS A POLICY

Why pr_merge needs a policy

An AI agent can call pr_merge faster than any human can review — one bad instruction and it creates or modifies resources in Pr Review by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

pr_merge Rate-limited

pr_merge 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": {
    "pr_merge": {
      "limits": [
        {
          "counter": "pr_merge_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 Pr Review, so you can run agents against it safely.

FAQ

Questions about pr_merge

What does the pr_merge tool do? +

Merge a pull request. Uses interactive elicitation for confirmation when supported, falls back to confirm=true parameter. It is categorised as a Write tool in the Pr Review MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on pr_merge? +

Register the Pr Review MCP server in PolicyLayer and add a rule for pr_merge: 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 Pr Review. Nothing to install.

What risk level is pr_merge? +

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

Can I rate-limit pr_merge? +

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

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

pr_merge is provided by the Pr Review MCP server (thebtf/pr-review-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.