AI agents use list_append to create or update resources in Amazon Translate MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Amazon Translate MCP Server environment.
The tool appends a value to a list, which is a write/modification operation. However, the description is minimal and uninformative, making it unclear what kind of list is being modified or the broader context. It appears to modify data reversibly (appending to a list), so Write is the most appropriate category.
From the tool's definition Tool name: 'list_append', description: 'Append value to list.'
Documented attack patterns abuse exactly the kind of access list_append gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Amazon Translate MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for list_append:
{
"version": "1",
"default": "deny",
"tools": {
"list_append": {
"limits": [
{
"counter": "list_append_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}list_append 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.
Free to start. No card required.
Append value to list. It is categorised as a Write tool in the Amazon Translate MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Amazon Translate MCP Server MCP server in PolicyLayer and add a rule for list_append: 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 Amazon Translate MCP Server. Nothing to install.
list_append 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 list_append 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 list_append. 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.
list_append is provided by the Amazon Translate MCP Server MCP server (awslabs.amazon-translate-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Amazon Translate MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
805 Amazon Translate MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.