Lookup a user by their email address
AI agents call lookup_user_by_email to retrieve information from MCP Server for Slack without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a simple data retrieval operation—looking up user profile information based on an email address. It has no side effects, does not modify data, and does not execute external operations. The blast radius of misuse is minimal: an AI agent could discover user information but cannot harm data or systems through this lookup alone. It is a straightforward Read operation.
From the tool's definition Tool name 'lookup_user_by_email' and description 'Lookup a user by their email address' indicate a query operation that retrieves user information without modifying or executing any actions.
Attacks that exploit this kind of access
Lookup a user by their email address. It is categorised as a Read tool in the MCP Server for Slack MCP Server, which means it retrieves data without modifying state.
Register the MCP Server for Slack MCP server in PolicyLayer and add a rule for lookup_user_by_email: 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 Server for Slack. Nothing to install.
lookup_user_by_email 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 lookup_user_by_email 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 lookup_user_by_email. 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.
lookup_user_by_email is provided by the MCP Server for Slack MCP server (z9905080/mcp-slack). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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