One payload said NoData and No Data, eight spellings of four severity words were two bands and six other vocabularies, and the page cut had five names: the daily summary speaks one band token on both SKUs, six inferred cuts become observed truncated + *_returned, and the census classifies every cut key and severity literal by what it is (partial #3653)

Darling/Darling.Tests/DarlingMcpHealthToolsTests.cs

@@ -450,7 +450,10 @@ deadlock row surviving there means the purge has not reached the day (data_state
             Assert.Contains("\"deadlock_count\":1", onItsOwnDay, StringComparison.Ordinal);
             var judged = JsonDocument.Parse(onItsOwnDay).RootElement;
             Assert.Equal("past_horizon", judged.GetProperty("data_state").GetString());
-            Assert.Equal("No Data", judged.GetProperty("overall_health").GetString());
+            /* #3653: one band, one spelling — overall_health carries the token health_band does ("NoData", not the
+               viewer label "No Data"). */
+            Assert.Equal("NoData", judged.GetProperty("overall_health").GetString());
+            Assert.Equal("NoData", judged.GetProperty("health_band").GetString());
             Assert.Contains("1 of 7 signal sources", judged.GetProperty("data_note").GetString(), StringComparison.Ordinal);
             Assert.DoesNotContain("Healthy", onItsOwnDay, StringComparison.Ordinal);
             Assert.Contains("2026-07-20", onItsOwnDay, StringComparison.Ordinal);

Darling/Darling.Tests/DarlingPgAutovacuumVerdictLiveTests.cs

@@ -123,12 +123,18 @@ so the figure the verdict came from is visible. */
                undersized call discloses its page scope (the get_pg_database_stats pattern). */
             Assert.Equal(3, payload.GetProperty("past_threshold_count").GetInt32());
             Assert.Equal(1, payload.GetProperty("growing_count").GetInt32());
-            Assert.False(payload.GetProperty("limit_reached").GetBoolean());
-
+            Assert.False(payload.GetProperty("truncated").GetBoolean());
+
+            /* #3653: the cut is OBSERVED off a limit + 1 fetch (#3594), so a limit of exactly the population
+               is complete and one below it is truncated with the page under its *_returned name. */
+            var whole = JsonDocument.Parse(
+                await DarlingMcpPgAutovacuumTools.GetPgAutovacuumHealth(dataSource, ServerName, 4, tables.Length)).RootElement;
+            Assert.False(whole.GetProperty("truncated").GetBoolean());
+            Assert.Equal(tables.Length, whole.GetProperty("tables_returned").GetInt32());
             var truncated = JsonDocument.Parse(
                 await DarlingMcpPgAutovacuumTools.GetPgAutovacuumHealth(dataSource, ServerName, 4, 2)).RootElement;
-            Assert.Equal(2, truncated.GetProperty("table_count").GetInt32());
-            Assert.True(truncated.GetProperty("limit_reached").GetBoolean());
+            Assert.Equal(2, truncated.GetProperty("tables_returned").GetInt32());
+            Assert.True(truncated.GetProperty("truncated").GetBoolean());
 
             bodySucceeded = true;
         }

Darling/Darling.Tests/McpFilterSemanticsLivePostgresTests.cs

@@ -253,7 +253,8 @@ NOT Healthy. */
             Assert.Equal(1, ghost.GetProperty("collection_runs").GetInt64());
             Assert.Equal("purged", ghost.GetProperty("data_state").GetString());
             Assert.Equal("NoData", ghost.GetProperty("health_band").GetString());
-            Assert.Equal("No Data", ghost.GetProperty("overall_health").GetString());
+            /* #3653: one band, one spelling \u2014 overall_health carries the same token health_band does. */
+            Assert.Equal("NoData", ghost.GetProperty("overall_health").GetString());
             Assert.Contains("PURGED", ghost.GetProperty("data_note").GetString(), StringComparison.Ordinal);
             Assert.Contains(expectedHorizon.ToString("yyyy-MM-dd"), ghost.GetProperty("data_note").GetString(), StringComparison.Ordinal);
 
@@ -296,7 +297,7 @@ await DarlingMcpTestData.ExecAsync(connection, ct,
             /* The single-day read of a past-horizon day is a DATA payload (the rows are there), not unavailable. */
             var singlePast = JsonDocument.Parse(await DarlingMcpHealthTools.GetDailySummary(postgres, ServerName, ghostDay.ToString("yyyy-MM-dd"))).RootElement;
             Assert.Equal("past_horizon", singlePast.GetProperty("data_state").GetString());
-            Assert.Equal("No Data", singlePast.GetProperty("overall_health").GetString());
+            Assert.Equal("NoData", singlePast.GetProperty("overall_health").GetString());
             await DarlingMcpTestData.ExecAsync(connection, ct, $"DELETE FROM deadlocks WHERE server_id = {ServerId}");
 
             /* The horizon is the store's EFFECTIVE retention: a fleet-wide override shortening one signal

Darling/Darling.Tests/McpPageContractTests.cs

@@ -799,10 +799,12 @@ public void PgServerConfig_NamesItsDenominators_InItsDescription()
     /// the way <see cref="NoTool_ReadsAParameterAsItsAbsoluteValue_OnEitherSku"/> sweeps <c>Math.Abs</c>, with
     /// the same population floor so a marker that stops matching cannot pass for free.
     ///
-    /// <para>What this does NOT sweep: <c>limit_reached = x.Count &gt;= limit</c>. That key says the page is as
-    /// long as the cap — true by construction — and its prose says "more MAY exist"; it is a weaker dialect,
-    /// not an inference, and whether it collapses into an observed <c>truncated</c> is the vocabulary lane's
-    /// call. <c>McpPayloadContractCensusTests</c> holds it in the truncation-key inventory.</para>
+    /// <para>What this does NOT sweep: <c>limit_reached = x.Count &gt;= limit</c>. That key said the page was as
+    /// long as the cap — true by construction — and its prose said "more MAY exist"; a weaker dialect, not an
+    /// inference, and the discriminator witness below keeps the non-match on record. The vocabulary lane
+    /// (#3653) then collapsed it: the four tools that spelled it moved onto <c>BoundPage</c> (they are in
+    /// <see cref="PgPagedToolsThroughTheHelper"/>) and <c>McpPayloadContractCensusTests.RetiredCutSpellings</c>
+    /// fails its return by name.</para>
     /// </summary>
     [Fact]
     public void NoTool_InfersTruncationFromItsCap_OnEitherSku()
@@ -848,13 +850,23 @@ public void NoTool_InfersTruncationFromItsCap_OnEitherSku()
     /// receive the <c>limit + 1</c> fetch and trim it; <c>DarlingMcpPgPlanToolsTests</c> executes both
     /// boundaries against the builders, and <see cref="McpPageContractLivePostgresTests.PgPagedTools_FlipTruncatedExactlyAtTheBoundary_AgainstDevPostgres"/>
     /// executes the deadlock and index reads against live Postgres.
+    ///
+    /// <para>#3653 (the vocabulary lane) added the four tools that had spelled the cut <c>limit_reached =
+    /// x.Count &gt;= limit</c> — the inference this file's sweep deliberately did not flag because the key said
+    /// "as long as the cap", not "more exist" — now on the same helper with <c>truncated</c> and a
+    /// <c>*_returned</c> page count. <c>McpPayloadContractCensusTests</c> holds the vocabulary half (the
+    /// retired spelling cannot return); this roster holds the page contract.</para>
     /// </summary>
     public static readonly (Type Tools, string ToolName, string? Builder, string ReadName, string Sql)[] PgPagedToolsThroughTheHelper =
     [
         (typeof(DarlingMcpPgDeadlockTools), "get_pg_deadlocks", null, nameof(DarlingPgDeadlockReader.DeadlocksSql), DarlingPgDeadlockReader.DeadlocksSql),
         (typeof(DarlingMcpPgPlanTools), "get_pg_plans", "BuildPlansJson", nameof(DarlingPgPlanCaptureReader.PgPlanCaptureSql), DarlingPgPlanCaptureReader.PgPlanCaptureSql),
         (typeof(DarlingMcpPgPlanTools), "get_pg_plan_capture_readiness", "BuildReadinessJson", nameof(DarlingPgPlanCaptureReadinessReader.PgPlanCaptureReadinessSql), DarlingPgPlanCaptureReadinessReader.PgPlanCaptureReadinessSql),
         (typeof(DarlingMcpPgIndexTools), "get_pg_index_bloat", null, nameof(DarlingPgIndexBloatReader.PgIndexBloatSql), DarlingPgIndexBloatReader.PgIndexBloatSql),
+        (typeof(DarlingMcpPgAutovacuumTools), "get_pg_autovacuum_health", null, nameof(DarlingPgAutovacuumReader.PgAutovacuumSql), DarlingPgAutovacuumReader.PgAutovacuumSql),
+        (typeof(DarlingMcpPgSessionStatesTools), "get_pg_session_states", null, nameof(DarlingPgSessionStatesReader.PgSessionStatesSql), DarlingPgSessionStatesReader.PgSessionStatesSql),
+        (typeof(DarlingMcpPgIndexUsageTools), "get_pg_index_usage", null, nameof(DarlingPgIndexUsageReader.PgIndexUsageSql), DarlingPgIndexUsageReader.PgIndexUsageSql),
+        (typeof(DarlingMcpPgTableBloatTools), "get_pg_table_bloat", null, nameof(DarlingPgTableBloatReader.PgTableBloatSql), DarlingPgTableBloatReader.PgTableBloatSql),
     ];
 
     [Fact]