stage_show_message

THE RISK

High Risk

Why stage_show_message needs a policy

This tool triggers an external action (displaying a message on stage screens in ProPresenter), which constitutes an Execute operation affecting live presentation hardware. Misuse could disrupt live events or services being broadcast.

From the tool's definition "Show a message on stage screens" — triggers an external operation that causes visible output on stage display hardware

Documented attack patterns abuse exactly the kind of access stage_show_message gives an agent:

POLICY

How to control stage_show_message

PolicyLayer is an MCP gateway — it sits between your AI agents and Propresenter, and nothing reaches the server without passing your rules. This is the rule we recommend for stage_show_message:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "stage_show_message": {
      "limits": [
        {
          "counter": "stage_show_message_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

stage_show_message stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

Create a free account and register Propresenter — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Propresenter tools

Destructive clear_layer Clear a specific layer (audio, props, messages, announcements, slide, media, video_input) Destructive messages_delete Delete a specific message Destructive props_clear Clear a specific prop from display Destructive props_delete Delete a specific prop Destructive props_delete_collection Delete a specific prop collection Destructive stage_delete_layout Delete a specific stage layout Execute clear_trigger_group Trigger a specific clear group Execute props_pause_auto_clear Pause auto-clear for a specific prop

All 177 Propresenter tools →

Execute tools on other servers

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Go deeper

High-risk tools in Propresenter → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about stage_show_message

What does the stage_show_message tool do? +

Show a message on stage screens. It is categorised as a Execute tool in the Propresenter MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on stage_show_message? +

Register the Propresenter MCP server in PolicyLayer and add a rule for stage_show_message: 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 Propresenter. Nothing to install.

What risk level is stage_show_message? +

stage_show_message is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit stage_show_message? +

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

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

stage_show_message is provided by the Propresenter MCP server (@alxpark/propresenter-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Propresenter tool call.

Start from Propresenter, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →