set_summary · Codex Peers MCP: Risk & Policy

WHAT IT DOES

What set_summary does on Codex Peers MCP

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

WHY IT NEEDS A POLICY

Why set_summary needs a policy

This tool modifies peer metadata (a status summary) on a shared broker to enable peer discovery. It is reversible (the summary can be updated or cleared), has no destructive or financial implications, and does not execute code or retrieve sensitive data.

From the tool's definition Tool description states 'Set a short status summary' — this is a write operation that creates or modifies a status field visible to other peers. The verb 'set' indicates data modification.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_summary Rate-limited

set_summary 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": {
    "set_summary": {
      "limits": [
        {
          "counter": "set_summary_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 Codex Peers MCP, so you can run agents against it safely.

FAQ

Questions about set_summary

What does the set_summary tool do? +

Set a short status summary so other peers can discover what this Codex session is working on. It is categorised as a Write tool in the Codex Peers MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_summary? +

Register the Codex Peers MCP server in PolicyLayer and add a rule for set_summary: 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 Codex Peers MCP. Nothing to install.

What risk level is set_summary? +

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

Can I rate-limit set_summary? +

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

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

set_summary is provided by the Codex Peers MCP server (jscianna/codex-peers-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.