diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0a5f41549..b918e89cc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,9 +1,10 @@
 # Changelog
 
-- `aircraft_in_area` and `vessels_in_area` take `group_by` and `stats`, so a
-  client can ask which operators or ship types dominate an area, or the average
-  altitude or speed, over every match instead of estimating from the returned
-  rows.
+- `aircraft_in_area` and `vessels_in_area` take `group_by` and `stats`, so an
+  MCP client can ask which countries, aircraft types or ship types dominate an
+  area, or the average altitude or speed, over every match instead of
+  estimating from the returned rows. Operator and type are counted only where
+  the feed reports them.
 
 - Treat explicitly current, complete empty vessel coverage as a successful update,
   clearing obsolete contacts while retaining stale or incomplete snapshots.
diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md
index f9e9c02a7..bdc9573b4 100644
--- a/docs/CURRENT-STATE.md
+++ b/docs/CURRENT-STATE.md
@@ -98,7 +98,8 @@ count every match by a field (`group_by`: operator, country or type for
 aircraft; type or destination for ships; the ten largest groups, then other and
 unknown counts; the summary says when a feed reports none of the field) and
 summarize airborne altitude and speed (`stats`: count, min, median, mean, max).
-Both cover all matches, not just the rows returned. Voice offers the same queries next to its app
+Both cover all matches, not just the rows returned; voice leaves these two
+tools out, so they reach MCP clients only. Voice offers the same queries next to its app
 actions: the session lists them, and the browser runs them through the same
 catalog, loaded on first use. See [tools and the MCP server](TOOLS.md).