Manages GTM built-in variables: list, create (enable), delete (disable).
AI agents call gtm_builtin_variable to permanently remove resources in Google Tag Manager MCP Server — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
The tool supports delete/disable operations on GTM built-in variables, which can irreversibly disrupt tag firing logic if variables are disabled. Since the most severe operation available is 'delete (disable)', which could break tracking configurations, this falls under Destructive.
From the tool's definition Manages GTM built-in variables: list, create (enable), delete (disable)
Attacks that exploit this kind of access
Manages GTM built-in variables: list, create (enable), delete (disable). It is categorised as a Destructive tool in the Google Tag Manager MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Google Tag Manager MCP Server MCP server in PolicyLayer and add a rule for gtm_builtin_variable: 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 Google Tag Manager MCP Server. Nothing to install.
gtm_builtin_variable is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the gtm_builtin_variable 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 gtm_builtin_variable. 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.
gtm_builtin_variable is provided by the Google Tag Manager MCP Server MCP server (metkamedia/gtm-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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