rrule_expand
Recurring Date (RRULE-lite) Expander — Expand a bounded recurrence rule (FREQ/INTERVAL/COUNT/UNTIL/BYDAY) into concrete occurrence datetimes.
This record as markdown: /tools/com-wingmanprotocol-agent-gateway/rrule-expand.md
What rrule_expand does on Gateway
AI agents call rrule_expand to retrieve information from Gateway without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
freq | string | Yes | DAILY | WEEKLY | MONTHLY | YEARLY |
byday | array | — | Weekly only: list of weekday codes, e.g. ['MO','WE','FR'] |
count | integer | — | Number of occurrences to return (default 10, max 200) |
until | string | — | Stop generating after this ISO 8601 datetime |
dtstart | string | Yes | Start datetime, ISO 8601 |
interval | integer | — | Repeat every N freq-units (default 1) |
Parameters from the server's own tool schema.
Why rrule_expand is rated Low
This is a utility calculator that parses and expands recurrence rules (following iCalendar RRULE semantics) into a list of datetime values. It performs no I/O, does not query or modify external state, and produces only a read-only result set derived from the input. Despite the name suggesting 'expansion,' the operation is immutable and non-destructive.
From the tool's definition Tool description states it 'Expand[s] a bounded recurrence rule... into concrete occurrence datetimes' — a pure computation that transforms input parameters into a deterministic output without side effects, data modification, or external operations.
Attacks that exploit this kind of access
The rule that runs rrule_expand safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Gateway, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For rrule_expand, this is the rule to start with:
rrule_expand 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 Gateway, apply this rule, and every rrule_expand call is checked against it from then on.
Questions about rrule_expand
Recurring Date (RRULE-lite) Expander — Expand a bounded recurrence rule (FREQ/INTERVAL/COUNT/UNTIL/BYDAY) into concrete occurrence datetimes. It is categorised as a Read tool in the Gateway MCP Server, which means it retrieves data without modifying state.
rrule_expand accepts 6 parameters: freq, byday, count, until, dtstart, interval. Required: freq, dtstart. The full parameter table on this page comes from the server's own tool schema.
Register the Gateway MCP server in PolicyLayer and add a rule for rrule_expand: 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 Gateway. Nothing to install.
rrule_expand 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 rrule_expand 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 rrule_expand. 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.
rrule_expand is provided by the Gateway MCP server (https://wingmanprotocol.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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