List all API keys from Resend. Returns API key names, IDs, and creation dates. Don
AI agents call list-api-keys 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 sensitive information (API keys and their metadata) without modifying or deleting data. While it is a Read operation, severity is high because API keys are sensitive credentials that, if exposed to an AI agent, could be used to authenticate unauthorized access to the Resend service. However, this tool itself only lists/retrieves, making it Read rather than a more severe category.
From the tool's definition Tool 'list-api-keys' returns API key names, IDs, and creation dates from Resend. The description explicitly states it 'List[s] all API keys', indicating data retrieval with no modification.
Documented attack patterns abuse exactly the kind of access list-api-keys 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-api-keys:
{
"version": "1",
"default": "deny",
"tools": {
"list-api-keys": {}
}
}list-api-keys is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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List all API keys from Resend. Returns API key names, IDs, and creation dates. 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-api-keys: 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-api-keys 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-api-keys 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-api-keys. 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-api-keys 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.
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77 Email Sending MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.