AI agents call list_event_types to retrieve information from Spline without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and returns information about available event types without modifying any data, executing external operations, or causing side effects. It is a straightforward informational read operation.
From the tool's definition Tool name is 'list_event_types' and description states it 'List all supported Spline event types' — a pure retrieval operation with no mutation or side effects.
Attacks that exploit this kind of access
List all supported Spline event types. It is categorised as a Read tool in the Spline MCP Server, which means it retrieves data without modifying state.
Register the Spline MCP server in PolicyLayer and add a rule for list_event_types: 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 Spline. Nothing to install.
list_event_types 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_event_types 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_event_types. 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_event_types is provided by the Spline MCP server (lesleslie/spline-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 →