# update_pull_request_branch

Update the branch of a pull request with the latest changes from the base branch.

Agent View of the PolicyLayer registry record for `update_pull_request_branch`. HTML page: https://policylayer.com/tools/github/update-pull-request-branch

## Facts

- Tool: `update_pull_request_branch`
- Server: GitHub (`oci:ghcr.io/github/github-mcp-server:1.3.0`) — https://policylayer.com/tools/github.md
- Homepage: https://github.com/github/github-mcp-server
- Risk category: Write (Medium risk)
- Registry record: grade D, identity verified
- Server auth posture: gated
- Server rate-limited: no
- Parameters: 4
- Recommended policy verdict: Rate-limited

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `repo` | string | no | Repository name |
| `owner` | string | no | Repository owner |
| `pullNumber` | number | no | Pull request number |
| `expectedHeadSha` | string | no | The expected SHA of the pull request's HEAD ref |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "update_pull_request_branch",
    "arguments": {}
  }
}
```

## Why update_pull_request_branch is rated Medium

This tool modifies the state of a pull request branch reversibly—it updates the branch to incorporate upstream changes, which is a standard git operation. It does not delete data (not Destructive), execute arbitrary code (not Execute), create new records (Write rather than just Create), or involve financial transactions (not Financial).

From the tool's own definition: "Tool performs an update operation on a pull request branch, modifying the branch state by incorporating latest changes from the base branch. The verb 'update' combined with 'branch' indicates data modification rather than retrieval or destruction."

## Use case

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

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches GitHub:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "update_pull_request_branch": {
      "limits": [
        {
          "counter": "update_pull_request_branch_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on GitHub (85)

- `delete_file` — Destructive — https://policylayer.com/tools/github/delete-file.md
- `projects_write` — Destructive — https://policylayer.com/tools/github/projects-write.md
- `actions_run_trigger` — Execute — https://policylayer.com/tools/github/actions-run-trigger.md
- `assign_copilot_to_issue` — Execute — https://policylayer.com/tools/github/assign-copilot-to-issue.md
- `actions_get` — Read — https://policylayer.com/tools/github/actions-get.md
- `actions_list` — Read — https://policylayer.com/tools/github/actions-list.md
- `get_code_scanning_alert` — Read — https://policylayer.com/tools/github/get-code-scanning-alert.md
- `get_commit` — Read — https://policylayer.com/tools/github/get-commit.md
- `get_copilot_job_status` — Read — https://policylayer.com/tools/github/get-copilot-job-status.md
- `get_copilot_space` — Read — https://policylayer.com/tools/github/get-copilot-space.md
- `get_dependabot_alert` — Read — https://policylayer.com/tools/github/get-dependabot-alert.md
- `get_discussion` — Read — https://policylayer.com/tools/github/get-discussion.md
- `get_discussion_comments` — Read — https://policylayer.com/tools/github/get-discussion-comments.md
- `get_file_contents` — Read — https://policylayer.com/tools/github/get-file-contents.md
- `get_gist` — Read — https://policylayer.com/tools/github/get-gist.md
- `get_global_security_advisory` — Read — https://policylayer.com/tools/github/get-global-security-advisory.md
- `get_job_logs` — Read — https://policylayer.com/tools/github/get-job-logs.md
- `get_label` — Read — https://policylayer.com/tools/github/get-label.md
- `get_latest_release` — Read — https://policylayer.com/tools/github/get-latest-release.md
- `get_me` — Read — https://policylayer.com/tools/github/get-me.md
- `get_notification_details` — Read — https://policylayer.com/tools/github/get-notification-details.md
- `get_release_by_tag` — Read — https://policylayer.com/tools/github/get-release-by-tag.md
- `get_repository_tree` — Read — https://policylayer.com/tools/github/get-repository-tree.md
- `get_secret_scanning_alert` — Read — https://policylayer.com/tools/github/get-secret-scanning-alert.md
- `get_tag` — Read — https://policylayer.com/tools/github/get-tag.md
- `get_team_members` — Read — https://policylayer.com/tools/github/get-team-members.md
- `get_teams` — Read — https://policylayer.com/tools/github/get-teams.md
- `github_support_docs_search` — Read — https://policylayer.com/tools/github/github-support-docs-search.md
- `issue_read` — Read — https://policylayer.com/tools/github/issue-read.md
- `list_branches` — Read — https://policylayer.com/tools/github/list-branches.md
- …and 55 more: https://policylayer.com/tools/github.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=github · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/github