mark_inbox_seen · Jikan MCP: Risk & Policy

WHAT IT DOES

What mark_inbox_seen does on Jikan

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

WHY IT NEEDS A POLICY

Why mark_inbox_seen needs a policy

This tool performs a state modification (marking a message as seen) which is typical Write category behavior. The operation is reversible (a message can be marked unseen again) and has minimal blast radius. Even if an AI agent marks all inbox messages as seen, the underlying messages remain intact and the action can be undone.

From the tool's definition Tool name is 'mark_inbox_seen' with description 'Mark an inbox message as seen.' This operation modifies the state of an inbox message from unseen to seen, which is a reversible state change.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mark_inbox_seen Rate-limited

mark_inbox_seen 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": {
    "mark_inbox_seen": {
      "limits": [
        {
          "counter": "mark_inbox_seen_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 Jikan, so you can run agents against it safely.

FAQ

Questions about mark_inbox_seen

What does the mark_inbox_seen tool do? +

Mark an inbox message as seen. Free (0 credits). It is categorised as a Write tool in the Jikan MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on mark_inbox_seen? +

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

What risk level is mark_inbox_seen? +

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

Can I rate-limit mark_inbox_seen? +

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

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

mark_inbox_seen is provided by the Jikan MCP server (thunderrabbit/jikan). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.