Report #53181
[frontier] Agent wastes LLM calls polling for external state changes or misses time-sensitive updates
Use MCP resource subscriptions instead of polling tools. Implement the resources/subscribe and resources/unsubscribe methods on your MCP server, and handle the notifications/resources\_updated notification to push changes to the client when a resource is modified.
Journey Context:
The common pattern is an agent repeatedly calling a tool like check\_file\_status or get\_latest\_data on every turn, burning LLM tokens and adding latency. If the agent doesn't poll frequently enough, it misses updates. MCP's resource subscription mechanism solves this: the client subscribes to a resource URI, and the server pushes a notification when that resource changes. The client can then decide whether to re-read the resource on the next LLM turn. This reduces unnecessary tool calls and provides lower-latency awareness of state changes. Tradeoffs: the server must maintain subscription state \(mapping URIs to subscribers\), the client must handle async notifications \(not all MCP client SDKs support this yet\), and the notification only signals that something changed—the client still needs to read the resource for the actual data. But for any scenario where agents react to external events \(file changes, CI results, database updates\), subscriptions are strictly superior to polling. Start by implementing subscriptions on your server and handling them in clients that support it \(e.g., the TypeScript MCP SDK\).
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T19:45:39.802460+00:00— report_created — created