Creates a named list of items for parallel processing. Use this tool when you need to perform the same operation across multiple files, URLs, or any collection of items. WHEN TO USE: - Before running shell commands or AI agents across multiple items - When you have a collection of file paths, URL...
AI agents use create_list to create or update resources in Par5 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Par5 environment.
This tool creates and stores data (a named list) in a reversible manner. It has no destructive capability, does not execute code or commands directly, and does not involve financial operations. While it facilitates parallel processing workflows, the tool itself only creates data structures. The impact is low because list creation is non-destructive and can be easily undone via delete_list.
From the tool's definition Tool creates a named list of items that persists for the session. The description states 'Creates a named list' and 'The list persists for the duration of the session', indicating data structure creation and storage.
Documented attack patterns abuse exactly the kind of access create_list gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Par5, and nothing reaches the server without passing your rules. This is the rule we recommend for create_list:
{
"version": "1",
"default": "deny",
"tools": {
"create_list": {
"limits": [
{
"counter": "create_list_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}create_list 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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Creates a named list of items for parallel processing. Use this tool when you need to perform the same operation across multiple files, URLs, or any collection of items. WHEN TO USE: - Before running shell commands or AI agents across multiple items - When you have a collection of file paths, URLs, identifiers, or any strings to process in parallel WORKFLOW: 1. Call create_list with your array of items 2. Use the returned list_id with run_shell_across_list or run_agent_across_list 3. The list persists for the duration of the session EXAMPLE: To process files [. It is categorised as a Write tool in the Par5 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Par5 MCP server in PolicyLayer and add a rule for create_list: 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 Par5. Nothing to install.
create_list 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 create_list 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 create_list. 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.
create_list is provided by the Par5 MCP server (mathematic-inc/par5-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Par5, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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8 Par5 tools catalogued and risk-classified — across an index of 43,000+ MCP servers.