update_evaluator · Respan MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_evaluator does on Respan MCP Server

AI agents use update_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 update_evaluator needs a policy

This tool modifies existing evaluator configurations reversibly. It falls under Write category as it creates or modifies data reversibly. Severity is medium because misconfiguration of evaluators could impact monitoring/evaluation pipelines, but the effect is reversible and limited to evaluation logic rather than core operational data or financial systems.

From the tool's definition Tool name is 'update_evaluator' and description states 'Update an existing evaluator', indicating modification of existing data without deletion or creation of new records.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_evaluator Rate-limited

update_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": {
    "update_evaluator": {
      "limits": [
        {
          "counter": "update_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 update_evaluator

What does the update_evaluator tool do? +

Update an existing evaluator. 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 update_evaluator? +

Register the Respan MCP Server MCP server in PolicyLayer and add a rule for update_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 update_evaluator? +

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

Can I rate-limit update_evaluator? +

Yes. Add a rate_limit block to the update_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 update_evaluator completely? +

Set action: deny in the PolicyLayer policy for update_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 update_evaluator? +

update_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.