MCP: Add profiler tools (maui_profiler_*)

src/Cli/Microsoft.Maui.Cli/DevFlow/DevFlowCliJsonContext.cs

@@ -22,4 +22,9 @@ namespace Microsoft.Maui.Cli.DevFlow;
 [JsonSerializable(typeof(AgentRegistration[]))]
 [JsonSerializable(typeof(BrokerState))]
 [JsonSerializable(typeof(RegistrationMessage))]
+[JsonSerializable(typeof(ProfilerCapabilities))]
+[JsonSerializable(typeof(ProfilerSessionInfo))]
+[JsonSerializable(typeof(ProfilerBatch))]
+[JsonSerializable(typeof(ProfilerHotspot))]
+[JsonSerializable(typeof(List<ProfilerHotspot>))]
 internal sealed partial class DevFlowCliJsonContext : JsonSerializerContext;

src/Cli/Microsoft.Maui.Cli/DevFlow/Mcp/McpServerHost.cs

@@ -37,7 +37,8 @@ public static async Task RunAsync()
 			.WithTools<PreferencesTools>()
 			.WithTools<PlatformTools>()
 			.WithTools<SensorTools>()
-			.WithTools<BatchTools>();
+			.WithTools<BatchTools>()
+			.WithTools<ProfilerTools>();
 
 		await builder.Build().RunAsync();
 	}

src/Cli/Microsoft.Maui.Cli/DevFlow/Mcp/Tools/ProfilerTools.cs

@@ -0,0 +1,99 @@
+using System.ComponentModel;
+using ModelContextProtocol.Server;
+using Microsoft.Maui.Cli.DevFlow.Mcp;
+
+namespace Microsoft.Maui.Cli.DevFlow.Mcp.Tools;
+
+[McpServerToolType]
+public sealed class ProfilerTools
+{
+	[McpServerTool(Name = "maui_profiler_capabilities"), Description("Get profiler capabilities for the connected agent. Call this first to check what profiling features are supported (FPS, memory, GC, CPU, jank detection, etc.) before starting a session.")]
+	public static async Task<string> GetCapabilities(
+		McpAgentSession session,
+		[Description("Agent HTTP port (optional if only one agent connected)")] int? agentPort = null)
+	{
+		var agent = await session.GetAgentClientAsync(agentPort);
+		var capabilities = await agent.GetProfilerCapabilitiesAsync();
+		if (capabilities == null)
+			return "Failed to get profiler capabilities. The agent may not support profiling.";
+
+		return CliJson.SerializeUntyped(capabilities, indented: false);
+	}
+
+	[McpServerTool(Name = "maui_profiler_start"), Description("Start a profiler session to collect performance samples (FPS, memory, GC, CPU). Returns session info with a sessionId for use with other profiler tools.")]
+	public static async Task<string> Start(
+		McpAgentSession session,
+		[Description("Sample collection interval in milliseconds (default: server-defined, typically 500ms)")] int? sampleIntervalMs = null,
+		[Description("Agent HTTP port (optional if only one agent connected)")] int? agentPort = null)
+	{
+		var agent = await session.GetAgentClientAsync(agentPort);
+		var sessionInfo = await agent.StartProfilerAsync(sampleIntervalMs);
+		if (sessionInfo == null)
+			return "Failed to start profiler session. Check maui_profiler_capabilities first.";
+
+		return CliJson.SerializeUntyped(sessionInfo, indented: false);
+	}
+
+	[McpServerTool(Name = "maui_profiler_stop"), Description("Stop an active profiler session. Returns the final session info with isActive=false.")]
+	public static async Task<string> Stop(
+		McpAgentSession session,
+		[Description("Session ID to stop (default: current active session)")] string? sessionId = null,
+		[Description("Agent HTTP port (optional if only one agent connected)")] int? agentPort = null)
+	{
+		var agent = await session.GetAgentClientAsync(agentPort);
+		var sessionInfo = await agent.StopProfilerAsync(sessionId);
+		if (sessionInfo == null)
+			return "Failed to stop profiler session. No active session found.";
+
+		return CliJson.SerializeUntyped(sessionInfo, indented: false);
+	}
+
+	[McpServerTool(Name = "maui_profiler_samples"), Description("Get profiler samples (FPS, memory, GC stats, CPU, jank events) from an active or stopped session. Uses cursor-based pagination — pass the returned cursor values in subsequent calls to get only new data.")]
+	public static async Task<string> GetSamples(
+		McpAgentSession session,
+		[Description("Session ID (default: current session)")] string? sessionId = null,
+		[Description("Sample cursor from previous response for incremental polling (default: 0 = from start)")] long sampleCursor = 0,
+		[Description("Marker cursor from previous response for incremental polling (default: 0 = from start)")] long markerCursor = 0,
+		[Description("Span cursor from previous response for incremental polling (default: 0 = from start)")] long spanCursor = 0,
+		[Description("Maximum number of samples to return (default: 500)")] int limit = 500,
+		[Description("Agent HTTP port (optional if only one agent connected)")] int? agentPort = null)
+	{
+		var agent = await session.GetAgentClientAsync(agentPort);
+		var batch = await agent.GetProfilerSamplesAsync(sessionId, sampleCursor, markerCursor, spanCursor, limit);
+		if (batch == null)
+			return "Failed to get profiler samples. No active session found.";
+
+		return CliJson.SerializeUntyped(batch, indented: false);
+	}
+
+	[McpServerTool(Name = "maui_profiler_hotspots"), Description("Get profiler hotspots — aggregated slow operations sorted by impact. Identifies the most expensive UI operations, navigation events, and other spans that exceed the duration threshold.")]
+	public static async Task<string> GetHotspots(
+		McpAgentSession session,
+		[Description("Maximum number of hotspots to return (default: 20, max: 200)")] int limit = 20,
+		[Description("Minimum duration in milliseconds to include (default: 16ms = one frame budget)")] int minDurationMs = 16,
+		[Description("Filter by span kind (e.g., 'ui.operation', 'navigation', 'http.request')")] string? kind = null,
+		[Description("Agent HTTP port (optional if only one agent connected)")] int? agentPort = null)
+	{
+		var agent = await session.GetAgentClientAsync(agentPort);
+		var hotspots = await agent.GetProfilerHotspotsAsync(limit, minDurationMs, kind);
+		if (hotspots.Count == 0)
+			return "No hotspots found matching the criteria.";
+
+		return CliJson.SerializeUntyped(hotspots, indented: false);
+	}
+
+	[McpServerTool(Name = "maui_profiler_marker"), Description("Publish a named marker into the profiler timeline. Use markers to annotate specific moments (e.g., 'user tapped login', 'data loaded') for correlation with performance data.")]
+	public static async Task<string> PublishMarker(
+		McpAgentSession session,
+		[Description("Marker name (e.g., 'user_tapped_login', 'page_loaded')")] string name,
+		[Description("Marker type category (default: 'user.action')")] string type = "user.action",
+		[Description("Optional JSON payload to attach to the marker")] string? payloadJson = null,
+		[Description("Agent HTTP port (optional if only one agent connected)")] int? agentPort = null)
+	{
+		var agent = await session.GetAgentClientAsync(agentPort);
+		var success = await agent.PublishProfilerMarkerAsync(name, type, payloadJson);
+		return success
+			? $"Marker '{name}' published successfully."
+			: $"Failed to publish marker '{name}'.";
+	}
+}