update_prompt · Prompt Store MCP: Risk & Policy

WHAT IT DOES

What update_prompt does on Prompt Store MCP

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

WHY IT NEEDS A POLICY

Why update_prompt needs a policy

The tool modifies data (prompts) in the local SQLite store, which is a Write operation. It is reversible (updates can be undone by updating again or reverting to backups), not destructive. The empty description lowers confidence slightly, but the tool name and sibling context (alongside delete_prompt, add_prompt) clearly establish its write nature.

From the tool's definition Tool name is 'update_prompt' on a Prompt Store MCP server that manages a SQLite database of prompts. The name and context indicate this modifies existing prompt records reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_prompt Rate-limited

update_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": {
    "update_prompt": {
      "limits": [
        {
          "counter": "update_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 Prompt Store MCP, so you can run agents against it safely.

FAQ

Questions about update_prompt

What does the update_prompt tool do? +

update_prompt. It is categorised as a Write tool in the Prompt Store 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 update_prompt? +

Register the Prompt Store MCP server in PolicyLayer and add a rule for update_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 Prompt Store MCP. Nothing to install.

What risk level is update_prompt? +

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

Can I rate-limit update_prompt? +

Yes. Add a rate_limit block to the update_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 update_prompt completely? +

Set action: deny in the PolicyLayer policy for update_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 update_prompt? +

update_prompt is provided by the Prompt Store MCP server (mhoshdev/prompt-store-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.