add_skill · Stac2026 MCP: Risk & Policy

WHAT IT DOES

What add_skill does on Stac2026

AI agents use add_skill to create or update resources in Stac2026 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Stac2026 environment.

WHY IT NEEDS A POLICY

Why add_skill needs a policy

This tool creates new records (skills) in a persistent system, modifying the agent's knowledge base and capabilities. While reversible (skills can presumably be deleted), it is a write operation that adds structured data to a personal infrastructure system.

From the tool's definition Tool name is 'add_skill' and description states 'Create a new custom skill' — the verb 'Create' indicates data creation. Parameters include name, description, and instruction content, which will be stored in the skill registry.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_skill Rate-limited

add_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": {
    "add_skill": {
      "limits": [
        {
          "counter": "add_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 Stac2026, so you can run agents against it safely.

FAQ

Questions about add_skill

What does the add_skill tool do? +

Create a new custom skill. Provide a name, description, and instruction content. It is categorised as a Write tool in the Stac2026 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_skill? +

Register the Stac2026 MCP server in PolicyLayer and add a rule for add_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 Stac2026. Nothing to install.

What risk level is add_skill? +

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

Can I rate-limit add_skill? +

Yes. Add a rate_limit block to the add_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 add_skill completely? +

Set action: deny in the PolicyLayer policy for add_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 add_skill? +

add_skill is provided by the Stac2026 MCP server (ktg-one/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.