tentative_invite · Nexus Core MCP: Risk & Policy

WHAT IT DOES

What tentative_invite does on Nexus Core

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

WHY IT NEEDS A POLICY

Why tentative_invite needs a policy

This tool creates or modifies data (RSVP status) reversibly—the user can change their response from 'tentative' to 'accept' or 'decline' later. It does not delete data, execute arbitrary code, move money, or trigger external operations with unpredictable side effects. The blast radius is limited to the user's calendar state and potentially notification to the event organizer.

From the tool's definition The tool 'respond' to an event invitation with a 'tentative' status modifies calendar/event data by setting the user's RSVP response. This is a state change operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

tentative_invite Rate-limited

tentative_invite 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": {
    "tentative_invite": {
      "limits": [
        {
          "counter": "tentative_invite_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 Nexus Core, so you can run agents against it safely.

FAQ

Questions about tentative_invite

What does the tentative_invite tool do? +

Respond 'tentative' to an event invitation. It is categorised as a Write tool in the Nexus Core MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on tentative_invite? +

Register the Nexus Core MCP server in PolicyLayer and add a rule for tentative_invite: 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 Nexus Core. Nothing to install.

What risk level is tentative_invite? +

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

Can I rate-limit tentative_invite? +

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

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

tentative_invite is provided by the Nexus Core MCP server (noumenon-ai/nexus-core). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.