Get real-time bus arrival information for a specific bus stop and optionally a specific service number. Returns estimated arrival times, bus locations, and crowding levels.
Part of the Singapore LTA DataMall MCP Server server.
Free to start. No card required.
AI agents call bus_arrival to retrieve information from Singapore LTA DataMall MCP Server 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 bus_arrival 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": {
"bus_arrival": {}
}
}See the full Singapore LTA DataMall MCP Server policy for all 7 tools.
These attack patterns abuse exactly the kind of access bus_arrival 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 real-time bus arrival information for a specific bus stop and optionally a specific service number. Returns estimated arrival times, bus locations, and crowding levels.. It is categorised as a Read tool in the Singapore LTA DataMall MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Singapore LTA DataMall MCP Server MCP server in PolicyLayer and add a rule for bus_arrival: 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 Singapore LTA DataMall MCP Server. Nothing to install.
bus_arrival 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 bus_arrival 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 bus_arrival. 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.
bus_arrival is provided by the Singapore LTA DataMall MCP Server MCP server (hithereiamaliff/mcp-ltadatamallsg). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 7 Singapore LTA DataMall MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.