Manage Kit custom subscriber fields — list all fields, create, rename, or delete (destructive). Actions: list, create, update, delete
AI agents call manage_custom_fields to permanently remove resources in Kit — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
The tool supports delete operations on custom subscriber fields, which is irreversible. Since the most severe applicable category must be chosen, and deletion of custom fields could cascade to loss of subscriber data across the entire account, this classifies as Destructive with high severity.
From the tool's definition 'delete (destructive)' explicitly called out in description; Actions include: list, create, update, delete
Attacks that exploit this kind of access
Manage Kit custom subscriber fields — list all fields, create, rename, or delete (destructive). Actions: list, create, update, delete. It is categorised as a Destructive tool in the Kit MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Kit MCP server in PolicyLayer and add a rule for manage_custom_fields: 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 Kit. Nothing to install.
manage_custom_fields 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 manage_custom_fields 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 manage_custom_fields. 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.
manage_custom_fields is provided by the Kit MCP server (@dancumberland/kit-mcp). 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.
Teams ship this data inside their own products. See what a licence covers →