simulate_principal_policy
AI agents call simulate_principal_policy to retrieve information from Awslabs Valkey without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool name suggests simulation/analysis of IAM policies for a principal, which is consistent with AWS IAM policy simulator functionality. This is a read operation that evaluates policies without making changes. However, confidence is moderate (0.6) because the description is empty, leaving some ambiguity about whether it might perform unexpected side effects or contain execute-like capabilities.
From the tool's definition Tool name is 'simulate_principal_policy' with no description provided. Based on the naming convention, 'simulate' typically indicates a non-destructive, read-only operation that tests or analyzes without modifying state.
Attacks that exploit this kind of access
simulate_principal_policy. It is categorised as a Read tool in the Awslabs Valkey MCP Server, which means it retrieves data without modifying state.
Register the Awslabs Valkey MCP server in PolicyLayer and add a rule for simulate_principal_policy: 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 Awslabs Valkey. Nothing to install.
simulate_principal_policy is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the simulate_principal_policy 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 simulate_principal_policy. 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.
simulate_principal_policy is provided by the Awslabs Valkey MCP server (awslabs.valkey-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.