list_calendars
List writable, non-hidden calendars that can be used as create_event or create_recurring_event targets. Use this before creating events when you need to choose a target calendarId explicitly.
This record as markdown: /tools/dugynoo-huly-mcp/list-calendars.md
What list_calendars does on Huly
AI agents call list_calendars to retrieve information from Huly without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Why list_calendars is rated Low
This tool retrieves and queries calendar metadata without creating, modifying, or deleting any data. It is purely informational, used to enumerate available calendars. The fact that it filters for 'writable, non-hidden' calendars is a descriptive filter, not a modification. The tool does not perform any irreversible or state-changing actions—it simply returns information to aid in subsequent decisions.
From the tool's definition Tool description states it 'List[s]' calendars and is used to query available calendars before performing write operations. The verb 'list' is a read-only operation with no side effects.
Attacks that exploit this kind of access
The rule that runs list_calendars safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Huly, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For list_calendars, this is the rule to start with:
list_calendars is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Huly, apply this rule, and every list_calendars call is checked against it from then on.
Questions about list_calendars
List writable, non-hidden calendars that can be used as create_event or create_recurring_event targets. Use this before creating events when you need to choose a target calendarId explicitly. It is categorised as a Read tool in the Huly MCP Server, which means it retrieves data without modifying state.
Register the Huly 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 Huly. 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 Huly MCP server (dugynoo/huly-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on Huly, and thousands of servers like it.
This server
Across the catalogue