AI agents use update_script to create or update resources in ServiceNow MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your ServiceNow MCP Server environment.
The name 'update_script' strongly implies modifying a script record in ServiceNow. Scripts can have significant impact (they execute server-side logic), so updating them could be high severity. However, since the description is empty, confidence is reduced. Categorized as Write (modifying an existing script record) rather than Execute, as 'update' implies persisting a change to a record rather than running it.
From the tool's definition Tool name 'update_script' on a server that manages scripts; description is empty and uninformative
Documented attack patterns abuse exactly the kind of access update_script gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and ServiceNow MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for update_script:
{
"version": "1",
"default": "deny",
"tools": {
"update_script": {
"limits": [
{
"counter": "update_script_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}update_script 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.
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update_script. It is categorised as a Write tool in the ServiceNow MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the ServiceNow MCP Server MCP server in PolicyLayer and add a rule for update_script: 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 ServiceNow MCP Server. Nothing to install.
update_script is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the update_script 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.
Set action: deny in the PolicyLayer policy for update_script. 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.
update_script is provided by the ServiceNow MCP Server MCP server (michaelbuckner/servicenow-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from ServiceNow MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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10 ServiceNow MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.