create_entry · MCP Auth MCP: Risk & Policy

WHAT IT DOES

What create_entry does on MCP Auth

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

WHY IT NEEDS A POLICY

Why create_entry needs a policy

The tool creates a new reversible entry in what appears to be a journal database. This is a Write operation: it modifies state by adding new data, but the action is reversible (entries can be deleted via the delete_entry sibling tool).

From the tool's definition Tool name is 'create_entry' and description states 'Create a new journal entry' — this creates new data in a journal system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_entry Rate-limited

create_entry 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_entry": {
      "limits": [
        {
          "counter": "create_entry_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 Auth, so you can run agents against it safely.

FAQ

Questions about create_entry

What does the create_entry tool do? +

Create a new journal entry. It is categorised as a Write tool in the MCP Auth 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_entry? +

Register the MCP Auth MCP server in PolicyLayer and add a rule for create_entry: 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 Auth. Nothing to install.

What risk level is create_entry? +

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

Can I rate-limit create_entry? +

Yes. Add a rate_limit block to the create_entry 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_entry completely? +

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

create_entry is provided by the MCP Auth MCP server (rubenpenap/mcp-auth). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.