List all contact properties from Resend. This tool is useful for getting property IDs and seeing which custom attributes are configured. If you need a contact property ID, you MUST use this tool to get all available properties and then ask the user to select the one they want. Don
AI agents call list-contact-properties to retrieve information from Email Sending MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and displays contact properties from Resend's system with no side effects. It performs a simple data retrieval operation to help users understand available properties before selecting one, which is a characteristic Read operation. The low severity reflects that unauthorized access would only expose metadata about property configurations without enabling harmful actions.
From the tool's definition Tool description states 'List all contact properties from Resend' and 'getting property IDs and seeing which custom attributes are configured.' The verb 'list' and the action of retrieving/querying data without modification indicates a read-only operation.
Documented attack patterns abuse exactly the kind of access list-contact-properties gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Email Sending MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for list-contact-properties:
{
"version": "1",
"default": "deny",
"tools": {
"list-contact-properties": {}
}
}list-contact-properties is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
List all contact properties from Resend. This tool is useful for getting property IDs and seeing which custom attributes are configured. If you need a contact property ID, you MUST use this tool to get all available properties and then ask the user to select the one they want. Don. It is categorised as a Read tool in the Email Sending MCP MCP Server, which means it retrieves data without modifying state.
Register the Email Sending MCP server in PolicyLayer and add a rule for list-contact-properties: 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 Email Sending MCP. Nothing to install.
list-contact-properties 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 list-contact-properties 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-contact-properties. 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-contact-properties is provided by the Email Sending MCP server (resend/resend-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 77 Email Sending MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
77 Email Sending MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.