Return a deterministic payload from a headless MCP tool.
AI agents call delayed_lookup to retrieve information from Mcp Registry Registry without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool performs a lookup operation that returns data deterministically. Lookups are read-only operations. The deterministic nature confirms predictable, non-mutative behavior. No evidence of write, delete, execute, or financial operations. Severity is low because read operations have minimal blast radius unless they expose highly sensitive data, which is not indicated here.
From the tool's definition Tool description states it 'Return[s] a deterministic payload', indicating data retrieval with no modification or side effects. The term 'payload' suggests query results or lookup results.
Attacks that exploit this kind of access
Return a deterministic payload from a headless MCP tool. It is categorised as a Read tool in the Mcp Registry Registry MCP Server, which means it retrieves data without modifying state.
Register the Mcp Registry Registry MCP server in PolicyLayer and add a rule for delayed_lookup: 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 Mcp Registry Registry. Nothing to install.
delayed_lookup 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 delayed_lookup 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 delayed_lookup. 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.
delayed_lookup is provided by the Mcp Registry Registry MCP server (@mastra/mcp-registry-registry). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →