assign_instrument_to_event · Redcap MCP: Risk & Policy

WHAT IT DOES

What assign_instrument_to_event does on Redcap

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

WHY IT NEEDS A POLICY

Why assign_instrument_to_event needs a policy

This tool modifies REDCap project structure by associating an instrument with an event, creating or updating relationships. This is reversible (can be unassigned or reassigned), making it Write rather than Destructive. Severity is medium because misconfiguration could disrupt research workflows and data integrity, but the effect is limited to relationship metadata rather than data loss.

From the tool's definition Tool name 'assign_instrument_to_event' indicates creation or modification of associations between instruments and events in REDCap.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

assign_instrument_to_event Rate-limited

assign_instrument_to_event 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": {
    "assign_instrument_to_event": {
      "limits": [
        {
          "counter": "assign_instrument_to_event_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 Redcap, so you can run agents against it safely.

FAQ

Questions about assign_instrument_to_event

What does the assign_instrument_to_event tool do? +

assign_instrument_to_event. It is categorised as a Write tool in the Redcap MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on assign_instrument_to_event? +

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

What risk level is assign_instrument_to_event? +

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

Can I rate-limit assign_instrument_to_event? +

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

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

assign_instrument_to_event is provided by the Redcap MCP server (msicilia/mcp-server-redcap). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.