add_prompt · Legal MCP Server MCP: Risk & Policy

WHAT IT DOES

What add_prompt does on Legal MCP Server

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

WHY IT NEEDS A POLICY

Why add_prompt needs a policy

This tool creates new entries in a prompt library without irreversible deletion, financial transactions, or arbitrary code execution. It's a straightforward data creation operation. Severity is low because prompts are typically text-based, user-contributed content with minimal blast radius if misused (worst case: unwanted prompts in a library that can be managed or removed).

From the tool's definition Tool description explicitly states 'Store a user-contributed prompt in the shared library' — a create/add operation that modifies data (the prompt library) reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_prompt Rate-limited

add_prompt 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": {
    "add_prompt": {
      "limits": [
        {
          "counter": "add_prompt_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 Legal MCP Server, so you can run agents against it safely.

FAQ

Questions about add_prompt

What does the add_prompt tool do? +

Store a user-contributed prompt in the shared library. It is categorised as a Write tool in the Legal 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 add_prompt? +

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

What risk level is add_prompt? +

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

Can I rate-limit add_prompt? +

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

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

add_prompt is provided by the Legal MCP Server MCP server (mcp-agent766/legal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.