diff --git a/docs/guide/advanced/pool.md b/docs/guide/advanced/pool.md
index 5ae745c19..f3be9cd44 100644
--- a/docs/guide/advanced/pool.md
+++ b/docs/guide/advanced/pool.md
@@ -104,7 +104,7 @@ class CustomPoolWorker implements PoolWorker {
   }
 
   async stop() {
-    // cleanup the state
+    // cleanup the state, the worker must not be reused after this
   }
 
   deserialize(data) {
@@ -115,6 +115,8 @@ class CustomPoolWorker implements PoolWorker {
 
 Your `CustomPoolRunner` will be controlling how your custom test runner worker life cycles and communication channel works. For example, your `CustomPoolRunner` could launch a `node:worker_threads` `Worker`, and provide communication via `Worker.postMessage` and `parentPort`.
 
+Vitest calls `stop` when the worker is no longer needed, at the latest when the test run ends, and starts a new worker for the next run. `stop` should tear down the worker's runtime: modules evaluated in a worker are not refreshed when files change, so a runtime kept alive across runs would execute stale code.
+
 In your worker file, you can import helper utilities from `vitest/worker`:
 
 ```ts [my-worker.ts]