docs: backfill XML documentation across 756 files

Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.

tests/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli.Tests/CommandCancellationTests.cs

@@ -18,6 +18,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli.Tests;
 [Trait("Category", "Unit")]
 public sealed class CommandCancellationTests
 {
+    /// <summary>Verifies that probe command gracefully handles cancellation during initialization.</summary>
     [Fact]
     public async Task ProbeCommand_swallows_cancellation_during_initialize()
     {
@@ -29,6 +30,7 @@ public sealed class CommandCancellationTests
         await Should.NotThrowAsync(async () => await sut.ExecuteAsync(console));
     }
 
+    /// <summary>Verifies that read command gracefully handles cancellation during initialization.</summary>
     [Fact]
     public async Task ReadCommand_swallows_cancellation_during_initialize()
     {
@@ -46,6 +48,7 @@ public sealed class CommandCancellationTests
         await Should.NotThrowAsync(async () => await sut.ExecuteAsync(console));
     }
 
+    /// <summary>Verifies that write command gracefully handles cancellation during initialization.</summary>
     [Fact]
     public async Task WriteCommand_swallows_cancellation_during_initialize()
     {

tests/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli.Tests/ModbusCommandBaseTests.cs

@@ -23,11 +23,18 @@ public sealed class ModbusCommandBaseTests
     [Command("noop-test", Description = "Test-only probe of ModbusCommandBase.BuildOptions.")]
     private sealed class ProbeOnly : ModbusCommandBase
     {
+        /// <inheritdoc />
         public override ValueTask ExecuteAsync(IConsole console) => default;
+
+        /// <summary>Invokes BuildOptions with the given tags.</summary>
+        /// <param name="tags">The list of tag definitions to build options for.</param>
         public ModbusDriverOptions Invoke(IReadOnlyList<ModbusTagDefinition> tags) => BuildOptions(tags);
+
+        /// <summary>Invokes ValidateEndpoint.</summary>
         public void InvokeValidate() => ValidateEndpoint();
     }
 
+    /// <summary>Verifies that BuildOptions disables probe for one-shot CLI runs.</summary>
     [Fact]
     public void BuildOptions_disables_probe_for_one_shot_cli_runs()
     {
@@ -39,6 +46,7 @@ public sealed class ModbusCommandBaseTests
         options.Probe.Enabled.ShouldBeFalse();
     }
 
+    /// <summary>Verifies that BuildOptions maps TimeoutMs to Timeout TimeSpan.</summary>
     [Fact]
     public void BuildOptions_maps_TimeoutMs_to_Timeout_TimeSpan()
     {
@@ -49,6 +57,7 @@ public sealed class ModbusCommandBaseTests
         options.Timeout.ShouldBe(TimeSpan.FromMilliseconds(7500));
     }
 
+    /// <summary>Verifies that BuildOptions AutoReconnect defaults to true when flag is unset.</summary>
     [Fact]
     public void BuildOptions_AutoReconnect_defaults_to_true_when_flag_unset()
     {
@@ -59,6 +68,7 @@ public sealed class ModbusCommandBaseTests
         options.AutoReconnect.ShouldBeTrue();
     }
 
+    /// <summary>Verifies that BuildOptions AutoReconnect becomes false when disable reconnect flag is set.</summary>
     [Fact]
     public void BuildOptions_AutoReconnect_becomes_false_when_disable_reconnect_flag_set()
     {
@@ -69,6 +79,7 @@ public sealed class ModbusCommandBaseTests
         options.AutoReconnect.ShouldBeFalse();
     }
 
+    /// <summary>Verifies that BuildOptions flows host, port, and unit through correctly.</summary>
     [Fact]
     public void BuildOptions_flows_host_port_unit_through()
     {
@@ -81,6 +92,7 @@ public sealed class ModbusCommandBaseTests
         options.UnitId.ShouldBe((byte)17);
     }
 
+    /// <summary>Verifies that BuildOptions forwards the tag list verbatim.</summary>
     [Fact]
     public void BuildOptions_forwards_tag_list_verbatim()
     {
@@ -96,6 +108,8 @@ public sealed class ModbusCommandBaseTests
 
     // --- Driver.Modbus.Cli-003: parse-time endpoint validation -------------------------------
 
+    /// <summary>Verifies that ValidateEndpoint rejects ports outside the range 1 to 65535.</summary>
+    /// <param name="port">The port value that should be rejected.</param>
     [Theory]
     [InlineData(0)]
     [InlineData(-1)]
@@ -109,6 +123,8 @@ public sealed class ModbusCommandBaseTests
         Should.Throw<CliFx.Exceptions.CommandException>(() => sut.InvokeValidate());
     }
 
+    /// <summary>Verifies that ValidateEndpoint accepts ports in the valid range.</summary>
+    /// <param name="port">The port value that should be accepted.</param>
     [Theory]
     [InlineData(1)]
     [InlineData(502)]
@@ -120,6 +136,8 @@ public sealed class ModbusCommandBaseTests
         Should.NotThrow(() => sut.InvokeValidate());
     }
 
+    /// <summary>Verifies that ValidateEndpoint rejects non-positive timeout values.</summary>
+    /// <param name="timeoutMs">The timeout value in milliseconds that should be rejected.</param>
     [Theory]
     [InlineData(0)]
     [InlineData(-1)]
@@ -131,6 +149,8 @@ public sealed class ModbusCommandBaseTests
         Should.Throw<CliFx.Exceptions.CommandException>(() => sut.InvokeValidate());
     }
 
+    /// <summary>Verifies that ValidateEndpoint rejects unit IDs outside the range 1 to 247.</summary>
+    /// <param name="unitId">The unit ID value that should be rejected.</param>
     [Theory]
     [InlineData(0)]   // broadcast — disallowed for unicast read/write requests
     [InlineData(248)]
@@ -142,6 +162,8 @@ public sealed class ModbusCommandBaseTests
         Should.Throw<CliFx.Exceptions.CommandException>(() => sut.InvokeValidate());
     }
 
+    /// <summary>Verifies that ValidateEndpoint accepts unit IDs in the valid range.</summary>
+    /// <param name="unitId">The unit ID value that should be accepted.</param>
     [Theory]
     [InlineData(1)]
     [InlineData(247)]
@@ -153,6 +175,7 @@ public sealed class ModbusCommandBaseTests
         Should.NotThrow(() => sut.InvokeValidate());
     }
 
+    /// <summary>Verifies that ValidateEndpoint accepts default options.</summary>
     [Fact]
     public void ValidateEndpoint_accepts_default_options()
     {

tests/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli.Tests/ProbeCommandTests.cs

@@ -15,6 +15,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli.Tests;
 [Trait("Category", "Unit")]
 public sealed class ProbeCommandTests
 {
+    /// <summary>Verifies that ComputeVerdict returns OK when driver state is Healthy and status is Good.</summary>
     [Fact]
     public void ComputeVerdict_returns_OK_when_state_is_Healthy_and_status_is_Good()
     {
@@ -23,6 +24,8 @@ public sealed class ProbeCommandTests
         verdict.ShouldContain("OK");
     }
 
+    /// <summary>Verifies that ComputeVerdict returns FAIL when driver state is not Healthy.</summary>
+    /// <param name="state">The driver state to test.</param>
     [Theory]
     [InlineData(DriverState.Faulted)]
     [InlineData(DriverState.Reconnecting)]
@@ -34,6 +37,8 @@ public sealed class ProbeCommandTests
         verdict.ShouldContain("FAIL");
     }
 
+    /// <summary>Verifies that ComputeVerdict returns FAIL when snapshot status is Bad even if driver is Healthy.</summary>
+    /// <param name="statusCode">The OPC UA status code to test.</param>
     [Theory]
     [InlineData(0x80050000u)] // BadCommunicationError
     [InlineData(0x800A0000u)] // BadTimeout
@@ -50,6 +55,7 @@ public sealed class ProbeCommandTests
         verdict.ShouldContain("FAIL");
     }
 
+    /// <summary>Verifies that ComputeVerdict returns DEGRADED for uncertain status with healthy driver.</summary>
     [Fact]
     public void ComputeVerdict_returns_DEGRADED_for_uncertain_status_with_healthy_driver()
     {

tests/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli.Tests/ReadCommandTests.cs

@@ -7,6 +7,11 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli.Tests;
 [Trait("Category", "Unit")]
 public sealed class ReadCommandTests
 {
+    /// <summary>Verifies that SynthesiseTagName produces a stable, readable tag name format.</summary>
+    /// <param name="region">The Modbus region.</param>
+    /// <param name="address">The register address.</param>
+    /// <param name="type">The Modbus data type.</param>
+    /// <param name="expected">The expected synthesised tag name string.</param>
     [Theory]
     [InlineData(ModbusRegion.HoldingRegisters, 100, ModbusDataType.UInt16, "HR[100]:UInt16")]
     [InlineData(ModbusRegion.Coils, 0, ModbusDataType.Bool, "Coil[0]:Bool")]

tests/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli.Tests/WriteCommandParseValueTests.cs

@@ -13,6 +13,9 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli.Tests;
 [Trait("Category", "Unit")]
 public sealed class WriteCommandParseValueTests
 {
+    /// <summary>Verifies that boolean parsing accepts multiple aliases for true and false.</summary>
+    /// <param name="raw">The raw string value to parse.</param>
+    /// <param name="expected">The expected boolean result.</param>
     [Theory]
     [InlineData("true", true)]
     [InlineData("false", false)]
@@ -27,6 +30,7 @@ public sealed class WriteCommandParseValueTests
         WriteCommand.ParseValue(raw, ModbusDataType.Bool).ShouldBe(expected);
     }
 
+    /// <summary>Verifies that boolean parsing rejects unrecognized string values.</summary>
     [Fact]
     public void ParseValue_Bool_rejects_unknown_strings()
     {
@@ -34,6 +38,7 @@ public sealed class WriteCommandParseValueTests
             () => WriteCommand.ParseValue("maybe", ModbusDataType.Bool));
     }
 
+    /// <summary>Verifies that Int16 parsing handles positive and negative values correctly.</summary>
     [Fact]
     public void ParseValue_Int16_parses_positive_and_negative()
     {
@@ -41,6 +46,7 @@ public sealed class WriteCommandParseValueTests
         WriteCommand.ParseValue("32767", ModbusDataType.Int16).ShouldBe((short)32767);
     }
 
+    /// <summary>Verifies that both UInt16 and Bcd16 parsing return ushort type values.</summary>
     [Fact]
     public void ParseValue_UInt16_and_Bcd16_both_yield_ushort()
     {
@@ -48,12 +54,14 @@ public sealed class WriteCommandParseValueTests
         WriteCommand.ParseValue("65535", ModbusDataType.Bcd16).ShouldBeOfType<ushort>();
     }
 
+    /// <summary>Verifies that Float32 parsing uses invariant culture with period as decimal separator.</summary>
     [Fact]
     public void ParseValue_Float32_uses_invariant_culture_period_as_decimal_separator()
     {
         WriteCommand.ParseValue("3.14", ModbusDataType.Float32).ShouldBe(3.14f);
     }
 
+    /// <summary>Verifies that Float64 parsing maintains precision for larger decimal values.</summary>
     [Fact]
     public void ParseValue_Float64_handles_larger_precision()
     {
@@ -62,12 +70,14 @@ public sealed class WriteCommandParseValueTests
         ((double)result).ShouldBe(2.718281828d, 0.0000001d);
     }
 
+    /// <summary>Verifies that String parsing returns the raw input without modification.</summary>
     [Fact]
     public void ParseValue_String_returns_raw_string_unmodified()
     {
         WriteCommand.ParseValue("hello world", ModbusDataType.String).ShouldBe("hello world");
     }
 
+    /// <summary>Verifies that BitInRegister parsing accepts boolean aliases.</summary>
     [Fact]
     public void ParseValue_BitInRegister_accepts_bool_aliases()
     {
@@ -75,12 +85,14 @@ public sealed class WriteCommandParseValueTests
         WriteCommand.ParseValue("0", ModbusDataType.BitInRegister).ShouldBe(false);
     }
 
+    /// <summary>Verifies that Int32 parsing handles negative maximum values correctly.</summary>
     [Fact]
     public void ParseValue_Int32_parses_negative_max()
     {
         WriteCommand.ParseValue("-2147483648", ModbusDataType.Int32).ShouldBe(int.MinValue);
     }
 
+    /// <summary>Verifies that parsing rejects non-numeric strings for numeric data types.</summary>
     [Fact]
     public void ParseValue_rejects_non_numeric_for_numeric_types()
     {

tests/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli.Tests/WriteCommandRegionValidationTests.cs

@@ -17,6 +17,10 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli.Tests;
 [Trait("Category", "Unit")]
 public sealed class WriteCommandRegionValidationTests
 {
+    /// <summary>Verifies that write to read-only regions is rejected before reaching the driver.</summary>
+    /// <param name="region">The read-only Modbus region to attempt a write against.</param>
+    /// <param name="type">The data type used in the write attempt.</param>
+    /// <param name="value">The raw string value supplied to the write command.</param>
     [Theory]
     [InlineData(ModbusRegion.DiscreteInputs, ModbusDataType.Bool, "0")]
     [InlineData(ModbusRegion.InputRegisters, ModbusDataType.UInt16, "1")]
@@ -38,6 +42,8 @@ public sealed class WriteCommandRegionValidationTests
             async () => await sut.ExecuteAsync(console));
     }
 
+    /// <summary>Verifies that Coils region requires Bool data type (Driver.Modbus.Cli-002).</summary>
+    /// <param name="type">The non-Bool data type that should be rejected for the Coils region.</param>
     [Theory]
     [InlineData(ModbusDataType.UInt16)]
     [InlineData(ModbusDataType.Int16)]