append-scratchpad · Scratchpad MCP: Risk & Policy

WHAT IT DOES

What append-scratchpad does on Scratchpad MCP

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

WHY IT NEEDS A POLICY

Why append-scratchpad needs a policy

This tool modifies an existing scratchpad by adding content to it. It is a reversible write operation (content can be removed or the scratchpad can be reset). It does not delete data, execute code, or involve financial transactions. Blast radius is low as it only affects shared scratchpad notes within a project scope.

From the tool's definition 'Append content to an existing scratchpad'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

append-scratchpad Rate-limited

append-scratchpad 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": {
    "append-scratchpad": {
      "limits": [
        {
          "counter": "append-scratchpad_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 Scratchpad MCP, so you can run agents against it safely.

FAQ

Questions about append-scratchpad

What does the append-scratchpad tool do? +

Append content to an existing scratchpad. It is categorised as a Write tool in the Scratchpad 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 append-scratchpad? +

Register the Scratchpad MCP server in PolicyLayer and add a rule for append-scratchpad: 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 Scratchpad MCP. Nothing to install.

What risk level is append-scratchpad? +

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

Can I rate-limit append-scratchpad? +

Yes. Add a rate_limit block to the append-scratchpad 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 append-scratchpad completely? +

Set action: deny in the PolicyLayer policy for append-scratchpad. 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 append-scratchpad? +

append-scratchpad is provided by the Scratchpad MCP server (pc035860/scratchpad-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.