bookmark-rename · Jj MCP: Risk & Policy

WHAT IT DOES

What bookmark-rename does on Jj

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

WHY IT NEEDS A POLICY

Why bookmark-rename needs a policy

Renaming a bookmark is a reversible metadata modification operation. It creates or modifies data (the bookmark name) but does not delete data, execute arbitrary code, move money, or trigger irreversible changes. This fits the Write category.

From the tool's definition Tool description states it can 'Rename a bookmark in a Jujutsu (jj) repository' and 'update bookmark names'. The parameters oldName and newName confirm this modifies existing bookmark metadata.

Risk signalsAdmin/system-level operation

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

bookmark-rename Rate-limited

bookmark-rename 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": {
    "bookmark-rename": {
      "limits": [
        {
          "counter": "bookmark-rename_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 Jj, so you can run agents against it safely.

FAQ

Questions about bookmark-rename

What does the bookmark-rename tool do? +

Rename a bookmark in a Jujutsu (jj) repository. Useful for updating bookmark names. Parameters: oldName (Current name of the bookmark), newName (New name for the bookmark), repoPath (Optional path to repo root or working directory), cwd (Optional working directory to run the command in). It is categorised as a Write tool in the Jj MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on bookmark-rename? +

Register the Jj MCP server in PolicyLayer and add a rule for bookmark-rename: 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 Jj. Nothing to install.

What risk level is bookmark-rename? +

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

Can I rate-limit bookmark-rename? +

Yes. Add a rate_limit block to the bookmark-rename 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 bookmark-rename completely? +

Set action: deny in the PolicyLayer policy for bookmark-rename. 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 bookmark-rename? +

bookmark-rename is provided by the Jj MCP server (jj-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.