show · Things App MCP: Risk & Policy

WHAT IT DOES

What show does on Things App MCP

AI agents invoke show to trigger actions in Things App MCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why show needs a policy

This tool performs a UI action (navigating/displaying a view) in an external application via the Things URL scheme or AppleScript. It doesn't read data back to the agent, write/modify data, or destroy anything — it triggers an external operation in the app. Execute is the most appropriate category since it causes a side effect (changing the application's UI state), even though the blast radius is very low.

From the tool's definition 'Navigate to and show a list, project, area, tag, or to-do in Things' — triggers a UI navigation action in the Things app, an external operation beyond simple data retrieval

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

show Rate-limited

show 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.

View as policy code

policy.json

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

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about show

What does the show tool do? +

Navigate to and show a list, project, area, tag, or to-do in Things. Built-in list IDs: inbox, today, anytime, upcoming, someday, logbook, tomorrow, deadlines, repeating, all-projects, logged-projects. It is categorised as a Execute tool in the Things App MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on show? +

Register the Things App MCP server in PolicyLayer and add a rule for show: 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 Things App MCP. Nothing to install.

What risk level is show? +

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

Can I rate-limit show? +

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

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

show is provided by the Things App MCP server (lucas-flatwhite/things-app-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.