List events in a window and attach a relational character (Mom, Friend, Coach, Past-you, etc.) plus per-event memory_context drawn from seeded memory, so Claude can compose one-sentence reminders that reference real prior events.
AI agents call enrich_with_character_reminders to retrieve information from Apple Calendar MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Even though enrich_with_character_reminders only reads data, uncontrolled read access leaks sensitive information and racks up API costs — an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Attacks that exploit this kind of access
List events in a window and attach a relational character (Mom, Friend, Coach, Past-you, etc.) plus per-event memory_context drawn from seeded memory, so Claude can compose one-sentence reminders that reference real prior events. It is categorised as a Read tool in the Apple Calendar MCP MCP Server, which means it retrieves data without modifying state.
Register the Apple Calendar MCP server in PolicyLayer and add a rule for enrich_with_character_reminders: 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 Apple Calendar MCP. Nothing to install.
enrich_with_character_reminders 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 enrich_with_character_reminders 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 enrich_with_character_reminders. 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.
enrich_with_character_reminders is provided by the Apple Calendar MCP server (yongzhe-wang/yapping-apple-calendar-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.