Set value at index in list.
AI agents use list_set to create or update resources in Amazon ElastiCache Memcached MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Amazon ElastiCache Memcached MCP Server environment.
The description indicates this tool sets/overwrites a value at a specific index in a list, which is a write/modify operation. However, there is a mismatch between the tool name 'list_set' and the description — in a Memcached context, 'list_set' likely sets (writes) a value at a given index in a list data structure. This is reversible (can be overwritten again), so Write is the most appropriate category.
From the tool's definition Tool name is 'list_set' and description says 'Set value at index in list'
Attacks that exploit this kind of access
Set value at index in list. It is categorised as a Write tool in the Amazon ElastiCache Memcached MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Amazon ElastiCache Memcached MCP Server MCP server in PolicyLayer and add a rule for list_set: 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 ElastiCache Memcached MCP Server. Nothing to install.
list_set 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_set 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_set. 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_set is provided by the Amazon ElastiCache Memcached MCP Server MCP server (awslabs.memcached-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.