This record as markdown: /tools/firebase-genkit/lookupusers.md
What lookupUsers does on Genkit MCP
AI agents call lookupUsers to retrieve information from Genkit MCP without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Why lookupUsers is rated Low
This tool retrieves user information without modifying, deleting, or executing external operations. The verb 'list' and the query nature of the operation place it squarely in the Read category. The severity is low as unauthorized access to a user list is typically less critical than destructive or financial operations, though context-dependent sensitivity of user data could elevate this in specific environments.
From the tool's definition Tool name 'lookupUsers' and description 'use this tool to list users' indicates a query/retrieval operation with no modification.
Attacks that exploit this kind of access
The rule that runs lookupUsers safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Genkit MCP, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For lookupUsers, this is the rule to start with:
lookupUsers is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Genkit MCP, apply this rule, and every lookupUsers call is checked against it from then on.
Questions about lookupUsers
use this tool to list users. It is categorised as a Read tool in the Genkit MCP MCP Server, which means it retrieves data without modifying state.
Register the Genkit MCP server in PolicyLayer and add a rule for lookupUsers: 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 Genkit MCP. Nothing to install.
lookupUsers 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 lookupUsers 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 lookupUsers. 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.
lookupUsers is provided by the Genkit MCP server (genkit-ai/genkit). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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