Events in [start, end] (ISO-8601). Default calendar = primary.
AI agents call list_events to retrieve information from Nexus Core without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves or queries calendar data with a time-based filter. It has no side effects, does not create, modify, or delete data, and does not execute code or trigger external operations. It is a straightforward read operation that fetches existing calendar event information, making it low severity even in a misuse scenario where an agent might retrieve sensitive calendar details.
From the tool's definition Tool name 'list_events' and description 'Events in [start, end]' indicates a query operation that retrieves calendar events within a specified time range. The verb 'list' is explicitly a read operation with no modification capability.
Attacks that exploit this kind of access
Events in [start, end] (ISO-8601). Default calendar = primary. It is categorised as a Read tool in the Nexus Core MCP Server, which means it retrieves data without modifying state.
Register the Nexus Core MCP server in PolicyLayer and add a rule for list_events: 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 Nexus Core. Nothing to install.
list_events 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_events 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_events. 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_events is provided by the Nexus Core MCP server (noumenon-ai/nexus-core). 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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