attach_note · Agent Evidence MCP: Risk & Policy

WHAT IT DOES

What attach_note does on Agent Evidence MCP

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

WHY IT NEEDS A POLICY

Why attach_note needs a policy

An AI agent can call attach_note faster than any human can review — one bad instruction and it creates or modifies resources in Agent Evidence MCP by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

attach_note Rate-limited

attach_note 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": {
    "attach_note": {
      "limits": [
        {
          "counter": "attach_note_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 Agent Evidence MCP, so you can run agents against it safely.

FAQ

Questions about attach_note

What does the attach_note tool do? +

Attach a human-readable note to an existing artifact. It is categorised as a Write tool in the Agent Evidence 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 attach_note? +

Register the Agent Evidence MCP server in PolicyLayer and add a rule for attach_note: 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 Agent Evidence MCP. Nothing to install.

What risk level is attach_note? +

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

Can I rate-limit attach_note? +

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

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

attach_note is provided by the Agent Evidence MCP server (xiexie-qiuligao/agent-evidence-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.