create_evaluator · Respan MCP Server MCP: Risk & Policy

WHAT IT DOES

What create_evaluator does on Respan MCP Server

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

WHY IT NEEDS A POLICY

Why create_evaluator needs a policy

The tool creates a new evaluator entity, which is a reversible modification of system data (evaluators can be updated or deleted). This is classic Write category behavior—creating new resources without destructive or financial implications.

From the tool's definition Tool name 'create_evaluator' and description 'Create a new evaluator (grader)' indicate creation of a new resource.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_evaluator Rate-limited

create_evaluator 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": {
    "create_evaluator": {
      "limits": [
        {
          "counter": "create_evaluator_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 Respan MCP Server, so you can run agents against it safely.

FAQ

Questions about create_evaluator

What does the create_evaluator tool do? +

Create a new evaluator (grader). Evaluators score LLM outputs. REQUIRED: name, type, score_value_type. TYPES: -. It is categorised as a Write tool in the Respan 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 create_evaluator? +

Register the Respan MCP Server MCP server in PolicyLayer and add a rule for create_evaluator: 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 Respan MCP Server. Nothing to install.

What risk level is create_evaluator? +

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

Can I rate-limit create_evaluator? +

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

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

create_evaluator is provided by the Respan MCP Server MCP server (respanai/respan-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.