get_collection_health's reading guide moves off tools/list (#3898)

Darling/Darling.Tests/CollectionOutputBesideCostTests.cs

@@ -579,7 +579,10 @@ public void BothSkusToolDescriptions_TeachThatACorrectZeroExists()
             var source = ReadRepoFile(relative);
 
             Assert.Contains("what it BOUGHT", source, StringComparison.Ordinal);
-            Assert.Contains("that zero was CORRECT", source, StringComparison.Ordinal);
+            /* #3898: the pg_deadlocks anecdote that used to carry "that zero was CORRECT" moved to the
+               CHANGELOG (D4); the rule it taught - a zero can be the healthy reading - stays in the tail
+               right after it, so the pin re-points to that rule instead of the story. */
+            Assert.Contains("would fire on the healthy quiet install", source, StringComparison.Ordinal);
             Assert.Contains("deliberately NOT a band", source, StringComparison.Ordinal);
             Assert.Contains("needs a grant", source, StringComparison.Ordinal);
         }

Darling/Darling.Tests/McpToolGuideHeads.Data.cs

@@ -21,6 +21,7 @@ public sealed class McpToolGuideHeadsDataTests
 {
     private static readonly string[] ConvertedTools =
     [
+        "get_collection_health",
         "get_file_io_stats",
         "get_perfmon_stats",
         "get_server_properties",
@@ -33,6 +34,11 @@ public sealed class McpToolGuideHeadsDataTests
     /// <summary>The per-tool guardrail phrase each head must state.</summary>
     private static readonly (string Tool, string Fact)[] HeadFacts =
     [
+        ("get_collection_health", "STOPPED (gate off) does not count as failing"),
+        ("get_collection_health", "rows_stored=0 is NOT a fault by itself"),
+        ("get_collection_health", "last_error is a sticky slot, not necessarily current"),
+        ("get_collection_health", "regressed_from_productive floors WARNING on an axis SEPARATE from failed_collector_count"),
+        ("get_collection_health", "alert_read_health uses a DIFFERENT since-restart window"),
         ("get_file_io_stats", "LATEST IS A TIME: the newest snapshot, not a window"),
         ("get_perfmon_stats", "LATEST IS A TIME: the newest snapshot, not a window"),
         ("get_server_properties", "LATEST IS A TIME: the newest snapshot, not a window"),

Darling/Darling.Tests/McpToolGuideTests.cs

@@ -8,6 +8,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.IO;
 using System.Linq;
 using System.Reflection;
@@ -16,6 +17,7 @@
 using System.Text.Json;
 using System.Text.RegularExpressions;
 using Microsoft.Extensions.DependencyInjection;
+using ModelContextProtocol.Server;
 using PerformanceMonitor.Alerting;
 using PerformanceMonitor.Common;
 using PerformanceMonitor.Darling.Service.Mcp;
@@ -171,17 +173,17 @@ public void GetToolGuide_ServesTails_AndTopics_AndReportsUnknownNames()
     public void GetToolGuide_WithNoArguments_IsTheIndex()
     {
         /* HostCatalog wires up exactly DarlingMcpHealthParserTools, DarlingMcpDataTools and
-           DarlingMcpToolGuideTools, so this fixture's own guide-bearing roster is a local, self-contained fact
-           about THIS test's host, not a family pin (that lives in McpToolGuideHeadsHealthParserTests). */
-        var fixtureToolsWithGuides = new[]
-        {
-            "get_file_io_stats",
-            "get_health_parser_cpu_tasks", "get_health_parser_io_issues", "get_health_parser_memory_broker",
-            "get_health_parser_memory_conditions", "get_health_parser_memory_node_oom", "get_health_parser_scheduler_issues",
-            "get_health_parser_severe_errors", "get_health_parser_significant_waits", "get_health_parser_system_health",
-            "get_perfmon_stats", "get_server_properties", "get_top_procedures_by_cpu", "get_top_queries_by_cpu",
-            "get_wait_stats", "list_servers",
-        };
+           DarlingMcpToolGuideTools, so the expected roster is every tool on those
+           types whose Description carries the marker. It is derived, not hand-kept: a hand-kept roster made
+           every content PR that converts one of these tools edit the same lines (#3898). */
+        var fixtureToolsWithGuides = new[] { typeof(DarlingMcpHealthParserTools), typeof(DarlingMcpDataTools), typeof(DarlingMcpToolGuideTools) }
+            .SelectMany(type => type.GetMethods(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static | BindingFlags.Instance))
+            .Select(method => (Tool: method.GetCustomAttribute<McpServerToolAttribute>(), Description: method.GetCustomAttribute<DescriptionAttribute>()))
+            .Where(m => m.Tool?.Name is not null && m.Description?.Description.Contains(McpToolGuide.Marker, StringComparison.Ordinal) == true)
+            .Select(m => m.Tool!.Name!)
+            .OrderBy(name => name, StringComparer.Ordinal)
+            .ToArray();
+        Assert.Contains("get_health_parser_system_health", fixtureToolsWithGuides);
 
         using var doc = JsonDocument.Parse(DarlingMcpToolGuideTools.GetToolGuide(HostCatalog(), null, null));
         var withGuides = doc.RootElement.GetProperty("tools_with_guides").EnumerateArray().Select(e => e.GetString()).ToArray();

Darling/Darling.Tests/McpToolsListBudget/DarlingMcpDataTools.txt

@@ -4,7 +4,7 @@ param get_blocking_stats.as_of 167
 param get_blocking_stats.hours_back 191
 param get_blocking_stats.server_name 28
 
-tool get_collection_health 21026
+tool get_collection_health 583
 param get_collection_health.server_name 28
 
 tool get_collection_log 6995

Lite.Tests/CollectionOutputBesideCostTests.cs

@@ -344,7 +344,10 @@ public void BothSkusToolDescriptions_TeachThatACorrectZeroExists()
             var source = File.ReadAllText(Path.Combine(RepoRoot(), relative));
 
             Assert.Contains("what it BOUGHT", source, StringComparison.Ordinal);
-            Assert.Contains("that zero was CORRECT", source, StringComparison.Ordinal);
+            /* #3898: the pg_deadlocks anecdote that used to carry "that zero was CORRECT" moved to the
+               CHANGELOG (D4); the rule it taught - a zero can be the healthy reading - stays in the tail
+               right after it, so the pin re-points to that rule instead of the story. */
+            Assert.Contains("would fire on the healthy quiet install", source, StringComparison.Ordinal);
             Assert.Contains("deliberately NOT a band", source, StringComparison.Ordinal);
             Assert.Contains("needs a grant", source, StringComparison.Ordinal);
         }

Lite.Tests/McpToolGuideHeads.Data.cs

@@ -20,6 +20,7 @@ public sealed class McpToolGuideHeadsDataTests
 {
     private static readonly string[] ConvertedTools =
     [
+        "get_collection_health",
         "get_file_io_stats",
         "get_perfmon_stats",
         "get_server_properties",
@@ -31,6 +32,11 @@ public sealed class McpToolGuideHeadsDataTests
 
     private static readonly (string Tool, string Fact)[] HeadFacts =
     [
+        ("get_collection_health", "STOPPED (gate off) does not count as failing"),
+        ("get_collection_health", "rows_stored=0 is NOT a fault by itself"),
+        ("get_collection_health", "last_error is a sticky slot, not necessarily current"),
+        ("get_collection_health", "regressed_from_productive floors WARNING on an axis SEPARATE from failed_collector_count"),
+        ("get_collection_health", "alert_read_health uses a DIFFERENT since-restart window"),
         ("get_file_io_stats", "LATEST IS A TIME: the newest snapshot, not a window"),
         ("get_perfmon_stats", "LATEST IS A TIME: the newest snapshot, not a window"),
         ("get_server_properties", "LATEST IS A TIME: the newest snapshot, not a window"),

Lite.Tests/McpToolGuideTests.cs

@@ -7,13 +7,15 @@
  */
 
 using System;
+using System.ComponentModel;
 using System.IO;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.CompilerServices;
 using System.Text.Json;
 using System.Text.RegularExpressions;
 using Microsoft.Extensions.DependencyInjection;
+using ModelContextProtocol.Server;
 using PerformanceMonitor.Common;
 using PerformanceMonitorLite.Mcp;
 using Xunit;
@@ -106,16 +108,17 @@ public void GetToolGuide_ServesTails_AndTopics_AndReportsUnknownNames()
     [Fact]
     public void GetToolGuide_WithNoArguments_IsTheIndex()
     {
-        /* HostCatalog wires up exactly McpHealthParserTools, McpDiscoveryTools and McpToolGuideTools, so this
-           fixture's own guide-bearing roster is a local, self-contained fact about THIS test's host, not a
-           family pin (that lives in McpToolGuideHeadsHealthParserTests). */
-        var fixtureToolsWithGuides = new[]
-        {
-            "get_health_parser_cpu_tasks", "get_health_parser_io_issues", "get_health_parser_memory_broker",
-            "get_health_parser_memory_conditions", "get_health_parser_memory_node_oom", "get_health_parser_scheduler_issues",
-            "get_health_parser_severe_errors", "get_health_parser_significant_waits", "get_health_parser_system_health",
-            "list_servers",
-        };
+        /* HostCatalog wires up exactly McpHealthParserTools, McpDiscoveryTools and McpToolGuideTools, so the expected roster is every tool on those
+           types whose Description carries the marker. It is derived, not hand-kept: a hand-kept roster made
+           every content PR that converts one of these tools edit the same lines (#3898). */
+        var fixtureToolsWithGuides = new[] { typeof(McpHealthParserTools), typeof(McpDiscoveryTools), typeof(McpToolGuideTools) }
+            .SelectMany(type => type.GetMethods(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static | BindingFlags.Instance))
+            .Select(method => (Tool: method.GetCustomAttribute<McpServerToolAttribute>(), Description: method.GetCustomAttribute<DescriptionAttribute>()))
+            .Where(m => m.Tool?.Name is not null && m.Description?.Description.Contains(McpToolGuide.Marker, StringComparison.Ordinal) == true)
+            .Select(m => m.Tool!.Name!)
+            .OrderBy(name => name, StringComparer.Ordinal)
+            .ToArray();
+        Assert.Contains("get_health_parser_system_health", fixtureToolsWithGuides);
 
         using var doc = JsonDocument.Parse(McpToolGuideTools.GetToolGuide(HostCatalog(), null, null));
         var withGuides = doc.RootElement.GetProperty("tools_with_guides").EnumerateArray().Select(e => e.GetString()).ToArray();

Lite.Tests/McpToolsListBudget/McpHealthTools.txt

@@ -4,7 +4,7 @@ param get_blocking_stats.as_of 167
 param get_blocking_stats.hours_back 191
 param get_blocking_stats.server_name 28
 
-tool get_collection_health 21026
+tool get_collection_health 583
 param get_collection_health.server_name 28
 
 tool get_collection_log 4405