Get a public overview of Callendar, a SaaS solution for WhatsApp® reminders, cancellations, and rescheduling for Calendly.
Part of the Callendar server.
Free to start. No card required.
AI agents call get_callendar_overview to retrieve information from Callendar without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though get_callendar_overview only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"get_callendar_overview": {}
}
}See the full Callendar policy for all 4 tools.
These attack patterns abuse exactly the kind of access get_callendar_overview gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Get a public overview of Callendar, a SaaS solution for WhatsApp® reminders, cancellations, and rescheduling for Calendly.. It is categorised as a Read tool in the Callendar MCP Server, which means it retrieves data without modifying state.
Register the Callendar MCP server in PolicyLayer and add a rule for get_callendar_overview: 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 Callendar. Nothing to install.
get_callendar_overview 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 get_callendar_overview 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 get_callendar_overview. 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.
get_callendar_overview is provided by the Callendar MCP server (https://app.callendar.de/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 4 Callendar tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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