snow_attach_file · Serac MCP: Risk & Policy

WHAT IT DOES

What snow_attach_file does on Serac

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

WHY IT NEEDS A POLICY

Why snow_attach_file needs a policy

The tool attaches files to existing ServiceNow records, which modifies those records. This is a Write operation since file attachments can be removed or replaced. Severity is medium because unauthorized file attachment could introduce malicious content into enterprise systems, but the attachment itself is not destructive (records remain intact) and does not inherently move money or execute arbitrary code.

From the tool's definition Attach files to ServiceNow records with validation and content type detection — this creates/modifies records by adding file attachments, a reversible write operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

snow_attach_file Rate-limited

snow_attach_file 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": {
    "snow_attach_file": {
      "limits": [
        {
          "counter": "snow_attach_file_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 Serac, so you can run agents against it safely.

FAQ

Questions about snow_attach_file

What does the snow_attach_file tool do? +

Attach files to ServiceNow records with validation and content type detection. It is categorised as a Write tool in the Serac MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on snow_attach_file? +

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

What risk level is snow_attach_file? +

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

Can I rate-limit snow_attach_file? +

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

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

snow_attach_file is provided by the Serac MCP server (serac-labs/serac). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.