Get all environment variables used in this project, with which files use them and which domains they belong to.
AI agents call get_env_vars to retrieve information from Carto MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries project metadata to retrieve information about environment variables. It performs no modifications, deletions, or external operations. However, environment variables often contain sensitive information (API keys, credentials, secrets), so exposure of this data to an unauthorized or compromised AI agent poses a medium-severity information disclosure risk.
From the tool's definition Tool name 'get_env_vars' and description 'Get all environment variables used in this project' indicate retrieval/querying of data with no side effects. The function explicitly retrieves and lists environment variables and their metadata (files, domains).
Documented attack patterns abuse exactly the kind of access get_env_vars gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Carto MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for get_env_vars:
{
"version": "1",
"default": "deny",
"tools": {
"get_env_vars": {}
}
}get_env_vars is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Get all environment variables used in this project, with which files use them and which domains they belong to. It is categorised as a Read tool in the Carto MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Carto MCP Server MCP server in PolicyLayer and add a rule for get_env_vars: 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 Carto MCP Server. Nothing to install.
get_env_vars 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 get_env_vars 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 get_env_vars. 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.
get_env_vars is provided by the Carto MCP Server MCP server (theanshsonkar/carto). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 22 Carto MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
22 Carto MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.