Low Risk

expand_rrule

Expand a recurrence rule (RRULE) into concrete event instances.

Part of the Temporal Cortex MCP MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.

AI agents call expand_rrule to retrieve information from Temporal Cortex MCP 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 expand_rrule 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.

temporal-cortex-cortex-mcp.yaml
tools:
  expand_rrule:
    rules:
      - action: allow

See the full Temporal Cortex MCP policy for all 12 tools.

Tool Name expand_rrule
Category Read
Risk Level Low

View all 12 tools →

Agents calling read-class tools like expand_rrule have been implicated in these attack patterns. Read the full case and prevention policy for each:

Browse the full MCP Attack Database →

Other tools in the Read risk category across the catalogue. The same policy patterns (rate-limit, allow) apply to each.

What does the expand_rrule tool do? +

Expand a recurrence rule (RRULE) into concrete event instances.. It is categorised as a Read tool in the Temporal Cortex MCP MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on expand_rrule? +

Add a rule in your Intercept YAML policy under the tools section for expand_rrule. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Temporal Cortex MCP MCP server.

What risk level is expand_rrule? +

expand_rrule is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit expand_rrule? +

Yes. Add a rate_limit block to the expand_rrule rule in your Intercept 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.

How do I block expand_rrule completely? +

Set action: deny in the Intercept policy for expand_rrule. 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.

What MCP server provides expand_rrule? +

expand_rrule is provided by the Temporal Cortex MCP MCP server (temporal-cortex/cortex-mcp). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policies on Temporal Cortex MCP

Open source. One binary. Zero dependencies.

npx -y @policylayer/intercept
github.com/policylayer/intercept →
// GET IN TOUCH

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