install_skill · skill4agent MCP Server MCP: Risk & Policy

WHAT IT DOES

What install_skill does on skill4agent MCP Server

AI agents use install_skill to create or update resources in skill4agent MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your skill4agent MCP Server environment.

WHY IT NEEDS A POLICY

Why install_skill needs a policy

Installing a skill modifies the system/environment by adding new capabilities. This is a reversible write-type action (skills can presumably be uninstalled), making Write the appropriate category. Severity is medium because installing unvetted AI skills could introduce malicious behavior, but the action itself is not inherently destructive or financial.

From the tool's definition 'install_skill' and 'Get installation methods for a skill' — installs a skill into the AI environment

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

install_skill Rate-limited

install_skill 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": {
    "install_skill": {
      "limits": [
        {
          "counter": "install_skill_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 skill4agent MCP Server, so you can run agents against it safely.

FAQ

Questions about install_skill

What does the install_skill tool do? +

Get installation methods for a skill.\n\nUse cases:\n- When you need to install a skill. It is categorised as a Write tool in the skill4agent 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 install_skill? +

Register the skill4agent MCP Server 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 skill4agent MCP Server. Nothing to install.

What risk level is install_skill? +

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

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 skill4agent MCP Server MCP server (osulivan/skill4agent-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.