update_pet · Petstore MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_pet does on Petstore MCP Server

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

WHY IT NEEDS A POLICY

Why update_pet needs a policy

This tool modifies pet records but does not permanently delete them or execute arbitrary code. The action is reversible—updates can be undone by subsequent updates. It falls under the Write category as it creates or modifies data reversibly. Severity is medium because incorrect updates could affect pet records and potentially impact business logic, but the action is not destructive or financial.

From the tool's definition Tool name 'update_pet' and description 'Update an existing pet' indicate modification of existing data in a reversible manner.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_pet Rate-limited

update_pet 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_pet": {
      "limits": [
        {
          "counter": "update_pet_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 Petstore MCP Server, so you can run agents against it safely.

FAQ

Questions about update_pet

What does the update_pet tool do? +

Update an existing pet. It is categorised as a Write tool in the Petstore MCP Server 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_pet? +

Register the Petstore MCP Server MCP server in PolicyLayer and add a rule for update_pet: 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 Petstore MCP Server. Nothing to install.

What risk level is update_pet? +

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

Can I rate-limit update_pet? +

Yes. Add a rate_limit block to the update_pet 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_pet completely? +

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

update_pet is provided by the Petstore MCP Server MCP server (raghavendraprakash/mcpforrestapis). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.