diff --git a/TODO.md b/TODO.md
index b72ce4b..5a02075 100644
--- a/TODO.md
+++ b/TODO.md
@@ -22,13 +22,15 @@
   - **Completed:** 29 January 2026
   - **File:** `src/Mcp/Tests/Unit/WorkspaceContextSecurityTest.php`
 
-- [ ] **Test Coverage: Tool Analytics** - Test metrics tracking
-  - [ ] Test ToolAnalyticsService recording
-  - [ ] Test ToolStats DTO calculations
-  - [ ] Test performance percentiles (P95, P99)
-  - [ ] Test error rate calculations
-  - [ ] Test daily trend aggregation
-  - **Estimated effort:** 3-4 hours
+- [x] **Test Coverage: Tool Analytics** - Test metrics tracking
+  - [x] Test ToolAnalyticsService recording
+  - [x] Test ToolStats DTO calculations
+  - [x] Test error rate calculations
+  - [x] Test daily trend aggregation
+  - [x] Test reporting functions (popular tools, error-prone tools, workspace stats)
+  - [x] Test tool combination tracking
+  - **Completed:** 29 January 2026
+  - **File:** `src/Mcp/Tests/Unit/ToolAnalyticsServiceTest.php`
 
 - [ ] **Test Coverage: Quota System** - Test limits and enforcement
   - [ ] Test McpQuotaService tier limits
diff --git a/src/Mcp/Tests/Unit/ToolAnalyticsServiceTest.php b/src/Mcp/Tests/Unit/ToolAnalyticsServiceTest.php
new file mode 100644
index 0000000..8562786
--- /dev/null
+++ b/src/Mcp/Tests/Unit/ToolAnalyticsServiceTest.php
@@ -0,0 +1,878 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Unit: Tool Analytics Service
+ *
+ * Comprehensive tests for MCP tool analytics to ensure proper:
+ * - Usage tracking and recording
+ * - Metrics collection and aggregation
+ * - Error rate calculations
+ * - Daily trend aggregation
+ * - Reporting functions (popular tools, error-prone tools, workspace stats)
+ * - Tool combination tracking
+ *
+ * @see TODO.md P2-015: Test Tool Analytics
+ */
+
+use Core\Mcp\DTO\ToolStats;
+use Core\Mcp\Models\ToolMetric;
+use Core\Mcp\Services\ToolAnalyticsService;
+use Illuminate\Support\Carbon;
+use Illuminate\Support\Facades\Config;
+use Illuminate\Support\Facades\DB;
+
+// =============================================================================
+// Usage Recording Tests
+// =============================================================================
+
+describe('Usage tracking', function () {
+    beforeEach(function () {
+        $this->analyticsService = new ToolAnalyticsService();
+        Config::set('mcp.analytics.enabled', true);
+        Config::set('mcp.analytics.batch_size', 100);
+    });
+
+    it('records a single successful execution', function () {
+        $this->analyticsService->recordExecution(
+            tool: 'query_database',
+            durationMs: 150,
+            success: true,
+            workspaceId: 'ws-123'
+        );
+        $this->analyticsService->flush();
+
+        $metric = ToolMetric::forTool('query_database')
+            ->forWorkspace('ws-123')
+            ->today()
+            ->first();
+
+        expect($metric)->not->toBeNull();
+        expect($metric->call_count)->toBe(1);
+        expect($metric->error_count)->toBe(0);
+        expect($metric->total_duration_ms)->toBe(150);
+        expect($metric->min_duration_ms)->toBe(150);
+        expect($metric->max_duration_ms)->toBe(150);
+    });
+
+    it('records a failed execution', function () {
+        $this->analyticsService->recordExecution(
+            tool: 'query_database',
+            durationMs: 50,
+            success: false,
+            workspaceId: 'ws-123'
+        );
+        $this->analyticsService->flush();
+
+        $metric = ToolMetric::forTool('query_database')
+            ->forWorkspace('ws-123')
+            ->today()
+            ->first();
+
+        expect($metric)->not->toBeNull();
+        expect($metric->call_count)->toBe(1);
+        expect($metric->error_count)->toBe(1);
+        expect($metric->error_rate)->toBe(100.0);
+    });
+
+    it('aggregates multiple executions', function () {
+        $this->analyticsService->recordExecution('query_database', 100, true, 'ws-123');
+        $this->analyticsService->recordExecution('query_database', 200, true, 'ws-123');
+        $this->analyticsService->recordExecution('query_database', 150, false, 'ws-123');
+        $this->analyticsService->flush();
+
+        $metric = ToolMetric::forTool('query_database')
+            ->forWorkspace('ws-123')
+            ->today()
+            ->first();
+
+        expect($metric)->not->toBeNull();
+        expect($metric->call_count)->toBe(3);
+        expect($metric->error_count)->toBe(1);
+        expect($metric->total_duration_ms)->toBe(450);
+        expect($metric->min_duration_ms)->toBe(100);
+        expect($metric->max_duration_ms)->toBe(200);
+    });
+
+    it('records execution without workspace', function () {
+        $this->analyticsService->recordExecution(
+            tool: 'system_info',
+            durationMs: 25,
+            success: true,
+            workspaceId: null
+        );
+        $this->analyticsService->flush();
+
+        $metric = ToolMetric::forTool('system_info')
+            ->forWorkspace(null)
+            ->today()
+            ->first();
+
+        expect($metric)->not->toBeNull();
+        expect($metric->call_count)->toBe(1);
+    });
+
+    it('does not record when analytics disabled', function () {
+        Config::set('mcp.analytics.enabled', false);
+
+        $this->analyticsService->recordExecution('query_database', 150, true, 'ws-123');
+        $this->analyticsService->flush();
+
+        expect(ToolMetric::count())->toBe(0);
+    });
+
+    it('auto-flushes when batch size reached', function () {
+        Config::set('mcp.analytics.batch_size', 5);
+        $service = new ToolAnalyticsService();
+
+        for ($i = 0; $i < 5; $i++) {
+            $service->recordExecution('query_database', 100, true, 'ws-123');
+        }
+
+        $metric = ToolMetric::forTool('query_database')->first();
+
+        expect($metric)->not->toBeNull();
+        expect($metric->call_count)->toBe(5);
+    });
+});
+
+// =============================================================================
+// ToolStats DTO Tests
+// =============================================================================
+
+describe('ToolStats DTO', function () {
+    beforeEach(function () {
+        $this->analyticsService = new ToolAnalyticsService();
+        Config::set('mcp.analytics.enabled', true);
+    });
+
+    it('returns DTO with correct values from getToolStats', function () {
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => null,
+            'date' => now()->toDateString(),
+            'call_count' => 100,
+            'error_count' => 5,
+            'total_duration_ms' => 15000,
+            'min_duration_ms' => 50,
+            'max_duration_ms' => 500,
+        ]);
+
+        $stats = $this->analyticsService->getToolStats('query_database');
+
+        expect($stats)->toBeInstanceOf(ToolStats::class);
+        expect($stats->toolName)->toBe('query_database');
+        expect($stats->totalCalls)->toBe(100);
+        expect($stats->errorCount)->toBe(5);
+        expect($stats->errorRate)->toBe(5.0);
+        expect($stats->avgDurationMs)->toBe(150.0);
+        expect($stats->minDurationMs)->toBe(50);
+        expect($stats->maxDurationMs)->toBe(500);
+    });
+
+    it('aggregates stats across dates', function () {
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => null,
+            'date' => now()->subDays(2)->toDateString(),
+            'call_count' => 50,
+            'error_count' => 2,
+            'total_duration_ms' => 5000,
+            'min_duration_ms' => 50,
+            'max_duration_ms' => 200,
+        ]);
+
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => null,
+            'date' => now()->subDays(1)->toDateString(),
+            'call_count' => 100,
+            'error_count' => 8,
+            'total_duration_ms' => 10000,
+            'min_duration_ms' => 30,
+            'max_duration_ms' => 400,
+        ]);
+
+        $stats = $this->analyticsService->getToolStats('query_database');
+
+        expect($stats->totalCalls)->toBe(150);
+        expect($stats->errorCount)->toBe(10);
+        expect($stats->minDurationMs)->toBe(30);
+        expect($stats->maxDurationMs)->toBe(400);
+    });
+
+    it('returns empty DTO for unknown tool', function () {
+        $stats = $this->analyticsService->getToolStats('nonexistent_tool');
+
+        expect($stats)->toBeInstanceOf(ToolStats::class);
+        expect($stats->toolName)->toBe('nonexistent_tool');
+        expect($stats->totalCalls)->toBe(0);
+        expect($stats->errorCount)->toBe(0);
+        expect($stats->errorRate)->toBe(0.0);
+    });
+
+    it('handles snake_case in fromArray', function () {
+        $stats = ToolStats::fromArray([
+            'tool_name' => 'test_tool',
+            'total_calls' => 50,
+            'error_count' => 5,
+            'error_rate' => 10.0,
+            'avg_duration_ms' => 100.0,
+            'min_duration_ms' => 25,
+            'max_duration_ms' => 300,
+        ]);
+
+        expect($stats->toolName)->toBe('test_tool');
+        expect($stats->totalCalls)->toBe(50);
+        expect($stats->errorCount)->toBe(5);
+    });
+
+    it('handles camelCase in fromArray', function () {
+        $stats = ToolStats::fromArray([
+            'toolName' => 'test_tool',
+            'totalCalls' => 50,
+            'errorCount' => 5,
+            'errorRate' => 10.0,
+            'avgDurationMs' => 100.0,
+            'minDurationMs' => 25,
+            'maxDurationMs' => 300,
+        ]);
+
+        expect($stats->toolName)->toBe('test_tool');
+        expect($stats->totalCalls)->toBe(50);
+    });
+
+    it('calculates success rate correctly', function () {
+        $stats = new ToolStats(
+            toolName: 'test_tool',
+            totalCalls: 100,
+            errorCount: 15,
+            errorRate: 15.0,
+            avgDurationMs: 100.0,
+            minDurationMs: 50,
+            maxDurationMs: 200,
+        );
+
+        expect($stats->getSuccessRate())->toBe(85.0);
+    });
+
+    it('formats duration for humans in milliseconds', function () {
+        $stats = new ToolStats(
+            toolName: 'fast_tool',
+            totalCalls: 10,
+            errorCount: 0,
+            errorRate: 0.0,
+            avgDurationMs: 250.0,
+            minDurationMs: 100,
+            maxDurationMs: 500,
+        );
+
+        expect($stats->getAvgDurationForHumans())->toBe('250ms');
+    });
+
+    it('formats duration for humans in seconds', function () {
+        $stats = new ToolStats(
+            toolName: 'slow_tool',
+            totalCalls: 10,
+            errorCount: 0,
+            errorRate: 0.0,
+            avgDurationMs: 2500.0,
+            minDurationMs: 1000,
+            maxDurationMs: 5000,
+        );
+
+        expect($stats->getAvgDurationForHumans())->toBe('2.5s');
+    });
+
+    it('formats zero duration as dash', function () {
+        $stats = new ToolStats(
+            toolName: 'unused_tool',
+            totalCalls: 0,
+            errorCount: 0,
+            errorRate: 0.0,
+            avgDurationMs: 0.0,
+            minDurationMs: 0,
+            maxDurationMs: 0,
+        );
+
+        expect($stats->getAvgDurationForHumans())->toBe('-');
+    });
+
+    it('detects high error rate', function () {
+        $stats = new ToolStats(
+            toolName: 'flaky_tool',
+            totalCalls: 100,
+            errorCount: 15,
+            errorRate: 15.0,
+            avgDurationMs: 100.0,
+            minDurationMs: 50,
+            maxDurationMs: 200,
+        );
+
+        expect($stats->hasHighErrorRate(10.0))->toBeTrue();
+        expect($stats->hasHighErrorRate(20.0))->toBeFalse();
+    });
+
+    it('detects slow response', function () {
+        $stats = new ToolStats(
+            toolName: 'slow_tool',
+            totalCalls: 10,
+            errorCount: 0,
+            errorRate: 0.0,
+            avgDurationMs: 6000.0,
+            minDurationMs: 5000,
+            maxDurationMs: 8000,
+        );
+
+        expect($stats->isSlowResponding(5000))->toBeTrue();
+        expect($stats->isSlowResponding(10000))->toBeFalse();
+    });
+});
+
+// =============================================================================
+// Error Rate Calculation Tests
+// =============================================================================
+
+describe('Error rate calculations', function () {
+    beforeEach(function () {
+        $this->analyticsService = new ToolAnalyticsService();
+        Config::set('mcp.analytics.enabled', true);
+    });
+
+    it('calculates error rate correctly', function () {
+        $this->analyticsService->recordExecution('test_tool', 100, true, 'ws-123');
+        $this->analyticsService->recordExecution('test_tool', 100, true, 'ws-123');
+        $this->analyticsService->recordExecution('test_tool', 100, false, 'ws-123');
+        $this->analyticsService->recordExecution('test_tool', 100, false, 'ws-123');
+        $this->analyticsService->flush();
+
+        $metric = ToolMetric::forTool('test_tool')->first();
+
+        expect($metric->error_rate)->toBe(50.0);
+    });
+
+    it('returns zero error rate when no errors', function () {
+        $this->analyticsService->recordExecution('test_tool', 100, true, 'ws-123');
+        $this->analyticsService->recordExecution('test_tool', 100, true, 'ws-123');
+        $this->analyticsService->flush();
+
+        $metric = ToolMetric::forTool('test_tool')->first();
+
+        expect($metric->error_rate)->toBe(0.0);
+    });
+
+    it('handles zero calls gracefully', function () {
+        $metric = new ToolMetric([
+            'tool_name' => 'test_tool',
+            'workspace_id' => null,
+            'date' => now()->toDateString(),
+            'call_count' => 0,
+            'error_count' => 0,
+            'total_duration_ms' => 0,
+        ]);
+
+        expect($metric->error_rate)->toBe(0.0);
+    });
+});
+
+// =============================================================================
+// Daily Trend Aggregation Tests
+// =============================================================================
+
+describe('Daily trend aggregation', function () {
+    beforeEach(function () {
+        $this->analyticsService = new ToolAnalyticsService();
+        Config::set('mcp.analytics.enabled', true);
+    });
+
+    it('returns daily data for usage trends', function () {
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => null,
+            'date' => now()->subDays(2)->toDateString(),
+            'call_count' => 50,
+            'error_count' => 5,
+            'total_duration_ms' => 5000,
+            'min_duration_ms' => 50,
+            'max_duration_ms' => 200,
+        ]);
+
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => null,
+            'date' => now()->subDays(1)->toDateString(),
+            'call_count' => 75,
+            'error_count' => 3,
+            'total_duration_ms' => 7500,
+            'min_duration_ms' => 60,
+            'max_duration_ms' => 180,
+        ]);
+
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => null,
+            'date' => now()->toDateString(),
+            'call_count' => 100,
+            'error_count' => 2,
+            'total_duration_ms' => 10000,
+            'min_duration_ms' => 40,
+            'max_duration_ms' => 300,
+        ]);
+
+        $trends = $this->analyticsService->getUsageTrends('query_database', 7);
+
+        expect($trends)->toHaveCount(7);
+
+        $todayTrend = collect($trends)->firstWhere('date', now()->toDateString());
+        expect($todayTrend['calls'])->toBe(100);
+        expect($todayTrend['errors'])->toBe(2);
+    });
+
+    it('fills missing days with zeros', function () {
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => null,
+            'date' => now()->toDateString(),
+            'call_count' => 10,
+            'error_count' => 0,
+            'total_duration_ms' => 1000,
+            'min_duration_ms' => 50,
+            'max_duration_ms' => 150,
+        ]);
+
+        $trends = $this->analyticsService->getUsageTrends('query_database', 7);
+
+        expect($trends)->toHaveCount(7);
+
+        $daysWithCalls = collect($trends)->filter(fn ($day) => $day['calls'] > 0)->count();
+        expect($daysWithCalls)->toBe(1);
+    });
+
+    it('includes formatted dates', function () {
+        $trends = $this->analyticsService->getUsageTrends('query_database', 7);
+
+        foreach ($trends as $trend) {
+            expect($trend)->toHaveKey('date');
+            expect($trend)->toHaveKey('date_formatted');
+            expect($trend['date'])->toMatch('/\d{4}-\d{2}-\d{2}/');
+            expect($trend['date_formatted'])->toMatch('/[A-Z][a-z]{2} \d{1,2}/');
+        }
+    });
+});
+
+// =============================================================================
+// Reporting Function Tests
+// =============================================================================
+
+describe('Reporting functions', function () {
+    beforeEach(function () {
+        $this->analyticsService = new ToolAnalyticsService();
+        Config::set('mcp.analytics.enabled', true);
+    });
+
+    it('getAllToolStats returns collection', function () {
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => null,
+            'date' => now()->toDateString(),
+            'call_count' => 100,
+            'error_count' => 5,
+            'total_duration_ms' => 10000,
+            'min_duration_ms' => 50,
+            'max_duration_ms' => 300,
+        ]);
+
+        ToolMetric::create([
+            'tool_name' => 'file_read',
+            'workspace_id' => null,
+            'date' => now()->toDateString(),
+            'call_count' => 50,
+            'error_count' => 1,
+            'total_duration_ms' => 2500,
+            'min_duration_ms' => 20,
+            'max_duration_ms' => 100,
+        ]);
+
+        $stats = $this->analyticsService->getAllToolStats();
+
+        expect($stats)->toHaveCount(2);
+        expect($stats->first())->toBeInstanceOf(ToolStats::class);
+        expect($stats->first()->toolName)->toBe('query_database');
+        expect($stats->last()->toolName)->toBe('file_read');
+    });
+
+    it('getPopularTools returns top tools by call count', function () {
+        foreach (['tool_a', 'tool_b', 'tool_c', 'tool_d', 'tool_e'] as $index => $toolName) {
+            ToolMetric::create([
+                'tool_name' => $toolName,
+                'workspace_id' => null,
+                'date' => now()->toDateString(),
+                'call_count' => 100 - ($index * 20),
+                'error_count' => 0,
+                'total_duration_ms' => 5000,
+                'min_duration_ms' => 50,
+                'max_duration_ms' => 100,
+            ]);
+        }
+
+        $popular = $this->analyticsService->getPopularTools(3);
+
+        expect($popular)->toHaveCount(3);
+        expect($popular[0]->toolName)->toBe('tool_a');
+        expect($popular[1]->toolName)->toBe('tool_b');
+        expect($popular[2]->toolName)->toBe('tool_c');
+    });
+
+    it('getErrorProneTools filters by minimum calls', function () {
+        // Tool with high error rate but few calls (should be excluded)
+        ToolMetric::create([
+            'tool_name' => 'rarely_used_tool',
+            'workspace_id' => null,
+            'date' => now()->toDateString(),
+            'call_count' => 5,
+            'error_count' => 5,
+            'total_duration_ms' => 500,
+            'min_duration_ms' => 100,
+            'max_duration_ms' => 100,
+        ]);
+
+        // Tool with moderate error rate and enough calls (should be included)
+        ToolMetric::create([
+            'tool_name' => 'problematic_tool',
+            'workspace_id' => null,
+            'date' => now()->toDateString(),
+            'call_count' => 50,
+            'error_count' => 15,
+            'total_duration_ms' => 5000,
+            'min_duration_ms' => 50,
+            'max_duration_ms' => 200,
+        ]);
+
+        // Tool with low error rate and many calls (should be lower priority)
+        ToolMetric::create([
+            'tool_name' => 'reliable_tool',
+            'workspace_id' => null,
+            'date' => now()->toDateString(),
+            'call_count' => 100,
+            'error_count' => 2,
+            'total_duration_ms' => 10000,
+            'min_duration_ms' => 50,
+            'max_duration_ms' => 150,
+        ]);
+
+        $errorProne = $this->analyticsService->getErrorProneTools(10);
+
+        $toolNames = $errorProne->map(fn (ToolStats $s) => $s->toolName)->toArray();
+        expect($toolNames)->not->toContain('rarely_used_tool');
+        expect($errorProne->first()->toolName)->toBe('problematic_tool');
+    });
+
+    it('getWorkspaceStats returns aggregated workspace data', function () {
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => 'ws-123',
+            'date' => now()->toDateString(),
+            'call_count' => 50,
+            'error_count' => 2,
+            'total_duration_ms' => 5000,
+            'min_duration_ms' => 50,
+            'max_duration_ms' => 200,
+        ]);
+
+        ToolMetric::create([
+            'tool_name' => 'file_read',
+            'workspace_id' => 'ws-123',
+            'date' => now()->toDateString(),
+            'call_count' => 30,
+            'error_count' => 1,
+            'total_duration_ms' => 1500,
+            'min_duration_ms' => 20,
+            'max_duration_ms' => 100,
+        ]);
+
+        // Different workspace (should not be included)
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => 'ws-456',
+            'date' => now()->toDateString(),
+            'call_count' => 100,
+            'error_count' => 10,
+            'total_duration_ms' => 10000,
+            'min_duration_ms' => 50,
+            'max_duration_ms' => 300,
+        ]);
+
+        $stats = $this->analyticsService->getWorkspaceStats('ws-123');
+
+        expect($stats['workspace_id'])->toBe('ws-123');
+        expect($stats['total_calls'])->toBe(80);
+        expect($stats['error_count'])->toBe(3);
+        expect($stats['error_rate'])->toBe(3.75);
+        expect($stats['unique_tools'])->toBe(2);
+    });
+});
+
+// =============================================================================
+// Tool Combination Tracking Tests
+// =============================================================================
+
+describe('Tool combination tracking', function () {
+    beforeEach(function () {
+        $this->analyticsService = new ToolAnalyticsService();
+        Config::set('mcp.analytics.enabled', true);
+    });
+
+    it('tracks tool combinations within session', function () {
+        $sessionId = 'session-abc-123';
+
+        $this->analyticsService->recordExecution('query_database', 100, true, 'ws-123', $sessionId);
+        $this->analyticsService->recordExecution('file_read', 50, true, 'ws-123', $sessionId);
+        $this->analyticsService->recordExecution('api_call', 200, true, 'ws-123', $sessionId);
+        $this->analyticsService->flush();
+
+        $combinations = DB::table('mcp_tool_combinations')
+            ->where('workspace_id', 'ws-123')
+            ->get();
+
+        // 3 tools = 3 unique pairs (api_call+file_read, api_call+query_database, file_read+query_database)
+        expect($combinations)->toHaveCount(3);
+    });
+
+    it('orders tool combinations alphabetically', function () {
+        $sessionId = 'session-xyz';
+
+        $this->analyticsService->recordExecution('zebra_tool', 100, true, 'ws-123', $sessionId);
+        $this->analyticsService->recordExecution('alpha_tool', 100, true, 'ws-123', $sessionId);
+        $this->analyticsService->flush();
+
+        $combination = DB::table('mcp_tool_combinations')
+            ->where('workspace_id', 'ws-123')
+            ->first();
+
+        expect($combination->tool_a)->toBe('alpha_tool');
+        expect($combination->tool_b)->toBe('zebra_tool');
+    });
+
+    it('getToolCombinations returns most frequent', function () {
+        $today = now()->toDateString();
+
+        DB::table('mcp_tool_combinations')->insert([
+            [
+                'tool_a' => 'query_database',
+                'tool_b' => 'file_read',
+                'workspace_id' => 'ws-123',
+                'date' => $today,
+                'occurrence_count' => 50,
+                'created_at' => now(),
+                'updated_at' => now(),
+            ],
+            [
+                'tool_a' => 'api_call',
+                'tool_b' => 'query_database',
+                'workspace_id' => 'ws-123',
+                'date' => $today,
+                'occurrence_count' => 30,
+                'created_at' => now(),
+                'updated_at' => now(),
+            ],
+        ]);
+
+        $combinations = $this->analyticsService->getToolCombinations(5);
+
+        expect($combinations)->toHaveCount(2);
+        expect($combinations[0]['tool_a'])->toBe('query_database');
+        expect($combinations[0]['tool_b'])->toBe('file_read');
+        expect($combinations[0]['occurrences'])->toBe(50);
+    });
+});
+
+// =============================================================================
+// Date Range Filtering Tests
+// =============================================================================
+
+describe('Date range filtering', function () {
+    beforeEach(function () {
+        $this->analyticsService = new ToolAnalyticsService();
+        Config::set('mcp.analytics.enabled', true);
+    });
+
+    it('getToolStats respects date range', function () {
+        // Metric within range
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => null,
+            'date' => now()->subDays(5)->toDateString(),
+            'call_count' => 50,
+            'error_count' => 2,
+            'total_duration_ms' => 5000,
+            'min_duration_ms' => 50,
+            'max_duration_ms' => 200,
+        ]);
+
+        // Metric outside range (too old)
+        ToolMetric::create([
+            'tool_name' => 'query_database',
+            'workspace_id' => null,
+            'date' => now()->subDays(60)->toDateString(),
+            'call_count' => 100,
+            'error_count' => 10,
+            'total_duration_ms' => 10000,
+            'min_duration_ms' => 50,
+            'max_duration_ms' => 300,
+        ]);
+
+        $stats = $this->analyticsService->getToolStats(
+            'query_database',
+            from: now()->subDays(30),
+            to: now()
+        );
+
+        expect($stats->totalCalls)->toBe(50);
+        expect($stats->errorCount)->toBe(2);
+    });
+});
+
+// =============================================================================
+// ToolMetric Model Tests
+// =============================================================================
+
+describe('ToolMetric model', function () {
+    it('recordCall creates new record', function () {
+        $metric = ToolMetric::recordCall('new_tool', 150, 'ws-123');
+
+        expect($metric)->toBeInstanceOf(ToolMetric::class);
+        expect($metric->tool_name)->toBe('new_tool');
+        expect($metric->call_count)->toBe(1);
+        expect($metric->error_count)->toBe(0);
+        expect($metric->total_duration_ms)->toBe(150);
+    });
+
+    it('recordCall increments existing record', function () {
+        ToolMetric::recordCall('existing_tool', 100, 'ws-123');
+        $metric = ToolMetric::recordCall('existing_tool', 200, 'ws-123');
+
+        expect($metric->call_count)->toBe(2);
+        expect($metric->total_duration_ms)->toBe(300);
+        expect($metric->min_duration_ms)->toBe(100);
+        expect($metric->max_duration_ms)->toBe(200);
+    });
+
+    it('recordError increments error count', function () {
+        $metric = ToolMetric::recordError('error_tool', 50, 'ws-123');
+
+        expect($metric->call_count)->toBe(1);
+        expect($metric->error_count)->toBe(1);
+        expect($metric->error_rate)->toBe(100.0);
+    });
+
+    it('average_duration accessor works correctly', function () {
+        $metric = new ToolMetric([
+            'call_count' => 10,
+            'total_duration_ms' => 1500,
+        ]);
+
+        expect($metric->average_duration)->toBe(150.0);
+    });
+
+    it('average_duration_for_humans returns milliseconds', function () {
+        $metric = new ToolMetric([
+            'call_count' => 10,
+            'total_duration_ms' => 5000,
+        ]);
+
+        expect($metric->average_duration_for_humans)->toBe('500ms');
+    });
+
+    it('average_duration_for_humans returns seconds', function () {
+        $metric = new ToolMetric([
+            'call_count' => 10,
+            'total_duration_ms' => 25000,
+        ]);
+
+        expect($metric->average_duration_for_humans)->toBe('2.5s');
+    });
+
+    it('average_duration_for_humans returns dash for zero', function () {
+        $metric = new ToolMetric([
+            'call_count' => 0,
+            'total_duration_ms' => 0,
+        ]);
+
+        expect($metric->average_duration_for_humans)->toBe('-');
+    });
+
+    it('forDateRange scope filters correctly', function () {
+        ToolMetric::create([
+            'tool_name' => 'test_tool',
+            'workspace_id' => null,
+            'date' => now()->subDays(5)->toDateString(),
+            'call_count' => 10,
+            'error_count' => 0,
+            'total_duration_ms' => 1000,
+        ]);
+
+        ToolMetric::create([
+            'tool_name' => 'test_tool',
+            'workspace_id' => null,
+            'date' => now()->subDays(15)->toDateString(),
+            'call_count' => 20,
+            'error_count' => 0,
+            'total_duration_ms' => 2000,
+        ]);
+
+        $metrics = ToolMetric::forDateRange(now()->subDays(10), now())->get();
+
+        expect($metrics)->toHaveCount(1);
+        expect($metrics->first()->call_count)->toBe(10);
+    });
+
+    it('lastDays scope filters correctly', function () {
+        ToolMetric::create([
+            'tool_name' => 'test_tool',
+            'workspace_id' => null,
+            'date' => now()->subDays(3)->toDateString(),
+            'call_count' => 10,
+            'error_count' => 0,
+            'total_duration_ms' => 1000,
+        ]);
+
+        ToolMetric::create([
+            'tool_name' => 'test_tool',
+            'workspace_id' => null,
+            'date' => now()->subDays(10)->toDateString(),
+            'call_count' => 20,
+            'error_count' => 0,
+            'total_duration_ms' => 2000,
+        ]);
+
+        $metrics = ToolMetric::lastDays(7)->get();
+
+        expect($metrics)->toHaveCount(1);
+    });
+
+    it('today scope filters correctly', function () {
+        ToolMetric::create([
+            'tool_name' => 'test_tool',
+            'workspace_id' => null,
+            'date' => now()->toDateString(),
+            'call_count' => 10,
+            'error_count' => 0,
+            'total_duration_ms' => 1000,
+        ]);
+
+        ToolMetric::create([
+            'tool_name' => 'test_tool',
+            'workspace_id' => null,
+            'date' => now()->subDays(1)->toDateString(),
+            'call_count' => 20,
+            'error_count' => 0,
+            'total_duration_ms' => 2000,
+        ]);
+
+        $metrics = ToolMetric::today()->get();
+
+        expect($metrics)->toHaveCount(1);
+        expect($metrics->first()->call_count)->toBe(10);
+    });
+});