diff --git a/docs/site/content/docs/cli/orchestration.mdx b/docs/site/content/docs/cli/orchestration.mdx
index 88355cb8c82..47725eeda8e 100644
--- a/docs/site/content/docs/cli/orchestration.mdx
+++ b/docs/site/content/docs/cli/orchestration.mdx
@@ -114,7 +114,7 @@ orca orchestration dispatch --task <taskId> --to <workerHandle> --inject --json
 ## Messaging notes
 
 - Default `check` is the bound Run's oldest unacked Delivery (FIFO). Replay until `--ack`.
-- `--peek` / `--all` do not consume mail.
+- `--peek` / `--all` do not consume mail and return no `deliveryId`, so they do not drain a mailbox on their own. `--all` and a Run `--peek` show at most 100 rows. To drain, repeat plain `check --ack <previous deliveryId>` until `deliveryId` is `null`.
 - Group addresses: `@all`, `@idle`, `@claude`, `@codex`, `@opencode`, `@gemini`, `@droid`, `@grok`, `@cursor`, `@worktree:<id>` — never for `worker_done` / heartbeat.
 - Every group except `@worktree:<id>` means the live Dispatches of the sender's own Run, delivered to their Dispatch mailboxes (or child Run mailboxes for nested coordinators). A sender in no Run is refused; `--run` must match the audience and never grants membership.
 - Run groups exclude their owning coordinator. A worker raising a blocker sends to `run:<id>`. `@worktree:<id>` includes coordinators in that workspace.
diff --git a/src/cli/specs/orchestration.ts b/src/cli/specs/orchestration.ts
index 20008e45749..df82997c9ce 100644
--- a/src/cli/specs/orchestration.ts
+++ b/src/cli/specs/orchestration.ts
@@ -117,7 +117,7 @@ export const ORCHESTRATION_COMMAND_SPECS: CommandSpec[] = [
       'On Windows PowerShell, quote comma-separated type filters, e.g. --types "worker_done,escalation".',
       '--types is the wake condition for --wait; a returned Delivery is always the whole FIFO batch, so it is never filtered by type. Without --wait it has no effect on consuming checks. Only --peek and --all filter their rows.',
       '--format renders the returned rows as local text only; it never writes to another terminal.',
-      'A bound Run replays the same Delivery until --ack or all its messages are marked read, even with --types; process every message before acknowledging. Several --wait calls may wait on one Run inbox; waiting reserves nothing, listeners woken together get the same Delivery, and a repeated --ack is a no-op.'
+      'A bound Run replays the same Delivery until --ack or all its messages are marked read, even with --types; process every message before acknowledging. Several --wait calls may wait on one Run inbox; waiting reserves nothing, listeners woken together get the same Delivery, and a repeated --ack is a no-op. --peek and --all return no deliveryId, so they do not drain a mailbox on their own; --all and a Run --peek show at most 100 rows. To drain, repeat plain check with --ack <previous deliveryId> until deliveryId is null.'
     ]
   },
   {