append_insight · MySQL- MCP: Risk & Policy

WHAT IT DOES

What append_insight does on MySQL-MCP

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

WHY IT NEEDS A POLICY

Why append_insight needs a policy

This tool creates or modifies data (a business insight/memo entry) without permanent deletion or financial impact. It falls under Write category because appending is a reversible operation. Severity is medium because misuse could result in unauthorized modification of business intelligence records, but the blast radius is limited to memo entries rather than core database structures.

From the tool's definition Tool name 'append_insight' and description 'Add a new business insight to the memo' indicate creation/modification of data (a memo entry). The verb 'append' confirms data is being added reversibly to a memo structure.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

append_insight Rate-limited

append_insight 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_insight": {
      "limits": [
        {
          "counter": "append_insight_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches MySQL-MCP, so you can run agents against it safely.

FAQ

Questions about append_insight

What does the append_insight tool do? +

Add a new business insight to the memo. It is categorised as a Write tool in the MySQL-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_insight? +

Register the MySQL- MCP server in PolicyLayer and add a rule for append_insight: 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 MySQL-MCP. Nothing to install.

What risk level is append_insight? +

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

Can I rate-limit append_insight? +

Yes. Add a rate_limit block to the append_insight 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_insight completely? +

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

append_insight is provided by the MySQL- MCP server (zajtools/zaj-mysql-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.