update_agent · Snak MCP: Risk & Policy

WHAT IT DOES

What update_agent does on Snak

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

WHY IT NEEDS A POLICY

Why update_agent needs a policy

This tool creates or modifies data in a reversible manner (updating agent properties, renaming, etc.) without permanently deleting data. It fits the Write category as changes can typically be undone by subsequent updates.

From the tool's definition Tool description states it 'Update/modify/change/rename specific properties of an existing agent configuration' which are reversible modifications to agent data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_agent Rate-limited

update_agent 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": {
    "update_agent": {
      "limits": [
        {
          "counter": "update_agent_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 Snak, so you can run agents against it safely.

FAQ

Questions about update_agent

What does the update_agent tool do? +

Update/modify/change/rename specific properties of an existing agent configuration. Use when user wants to modify, change, update, edit, or rename any agent property like name, description, group, etc. It is categorised as a Write tool in the Snak MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_agent? +

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

What risk level is update_agent? +

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

Can I rate-limit update_agent? +

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

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

update_agent is provided by the Snak MCP server (kasarlabs/snak). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.