List all calendars accessible to the user
AI agents call list_calendars to retrieve information from Google Calendar MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and queries calendar metadata without side effects. It does not create, modify, delete, or execute any operations on calendar data. The action is purely informational, making it a Read category tool with low severity since calendar metadata listing poses minimal security risk even if misused by an AI agent.
From the tool's definition Tool name and description indicate 'List all calendars accessible to the user' - a retrieval operation with no modification or deletion capability.
Attacks that exploit this kind of access
List all calendars accessible to the user. It is categorised as a Read tool in the Google Calendar MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Google Calendar MCP Server MCP server in PolicyLayer and add a rule for list_calendars: 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 Calendar MCP Server. Nothing to install.
list_calendars 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_calendars 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_calendars. 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_calendars is provided by the Google Calendar MCP Server MCP server (kashyab19/google-calendar-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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