install_skill · Memex MCP: Risk & Policy

WHAT IT DOES

What install_skill does on Memex

AI agents invoke install_skill to trigger actions in Memex. 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 install_skill needs a policy

The name 'install_skill' strongly implies installing or loading some capability/module into the agent or system, which is an Execute-level action (triggering an external operation or modifying runtime behavior). However, the empty description significantly reduces confidence.

From the tool's definition Tool name 'install_skill' — description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

install_skill Rate-limited

install_skill 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": {
    "install_skill": {
      "limits": [
        {
          "counter": "install_skill_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 Memex, so you can run agents against it safely.

FAQ

Questions about install_skill

What does the install_skill tool do? +

install_skill. It is categorised as a Execute tool in the Memex MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on install_skill? +

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

What risk level is install_skill? +

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

Can I rate-limit install_skill? +

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

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

install_skill is provided by the Memex MCP server (queflyhq/memex). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.