Create a WhatsApp® contact link so a user can talk with a Callendar expert. This does not send any message automatically.
Part of the Callendar server.
Free to start. No card required.
AI agents use create_callendar_contact_link to create or modify resources in Callendar. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call create_callendar_contact_link repeatedly, creating or modifying resources faster than any human could review. PolicyLayer's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Callendar.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"create_callendar_contact_link": {
"limits": [
{
"counter": "create_callendar_contact_link_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Callendar policy for all 4 tools.
These attack patterns abuse exactly the kind of access create_callendar_contact_link gives an agent. Each links to the full case and the policy that stops it:
Other write tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Create a WhatsApp® contact link so a user can talk with a Callendar expert. This does not send any message automatically.. It is categorised as a Write tool in the Callendar MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Callendar MCP server in PolicyLayer and add a rule for create_callendar_contact_link: 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.
create_callendar_contact_link is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the create_callendar_contact_link 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 create_callendar_contact_link. 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.
create_callendar_contact_link 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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