update_pull_request_branch · GitHub MCP Server MCP

WHAT IT DOES

What update_pull_request_branch does on GitHub MCP Server

AI agents invoke update_pull_request_branch to trigger actions in GitHub MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why update_pull_request_branch needs a policy

This tool triggers a branch merge/rebase operation on GitHub — it executes a Git operation (merging base branch changes into the PR branch) that has real side effects on remote branch state. It is not a simple write (creating/modifying a file) nor purely destructive, but it does execute an external operation whose effects depend on the repository state and arguments.

From the tool's definition Update a pull request branch with the latest changes from the base branch

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_pull_request_branch Rate-limited

update_pull_request_branch stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "update_pull_request_branch": {
      "limits": [
        {
          "counter": "update_pull_request_branch_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about update_pull_request_branch

What does the update_pull_request_branch tool do? +

Update a pull request branch with the latest changes from the base branch. It is categorised as a Execute tool in the GitHub MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on update_pull_request_branch? +

Register the GitHub MCP Server MCP server in PolicyLayer and add a rule for update_pull_request_branch: 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 GitHub MCP Server. Nothing to install.

What risk level is update_pull_request_branch? +

update_pull_request_branch is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit update_pull_request_branch? +

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

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

update_pull_request_branch is provided by the GitHub MCP Server MCP server (tuanle96/mcp-github). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.