diff --git a/php/Boot.php b/php/Boot.php
index 14565c4a..f611297e 100644
--- a/php/Boot.php
+++ b/php/Boot.php
@@ -9,7 +9,6 @@
 use Core\Events\AdminPanelBooting;
 use Core\Events\ApiRoutesRegistering;
 use Core\Events\ConsoleBooting;
-use Core\Events\McpToolsRegistering;
 use Core\Mod\Agentic\Services\AgenticManager;
 use Core\Mod\Agentic\Services\AgentResourceRegistry;
 use Core\Mod\Agentic\Services\AgentToolRegistry;
@@ -34,7 +33,6 @@ class Boot extends ServiceProvider
         AdminPanelBooting::class => 'onAdminPanel',
         ApiRoutesRegistering::class => 'onApiRoutes',
         ConsoleBooting::class => 'onConsole',
-        McpToolsRegistering::class => 'onMcpTools',
     ];
 
     public function boot(): void
@@ -98,6 +96,8 @@ public function register(): void
         $this->app->singleton(AgenticManager::class);
         $this->app->singleton(AgentToolRegistry::class);
 
+        $this->registerAgentTools();
+
         // Resources are bound here rather than hung off an event the way tools
         // are. There is no McpResourcesRegistering to listen for, and $listens
         // is populated by ModuleScanner from app/Core|Mod|Website only — dead
@@ -215,16 +215,30 @@ public function onConsole(ConsoleBooting $event): void
     }
 
     /**
-     * Handle MCP tools registration event.
+     * Fill the tool registry.
+     *
+     * Called from register(), not from the McpToolsRegistering event this used
+     * to listen for. $listens is populated by ModuleScanner scanning
+     * app/Core|Mod|Website only, so it is dead once this package is installed
+     * under vendor/: the event never fired and the registry stayed empty, which
+     * is half of why the stdio server advertised no tools. The other half was
+     * that it read a different registry entirely — see listTools() on the class
+     * this fills.
      *
-     * Note: Agent tools (plan_create, session_start, etc.) are implemented in
-     * the Mcp module at Mod\Mcp\Tools\Agent\* and registered via AgentToolRegistry.
-     * Brain tools are registered here as they belong to the Agentic module.
+     * @example
+     * $this->registerAgentTools();
      */
-    public function onMcpTools(McpToolsRegistering $event): void
+    private function registerAgentTools(): void
     {
         $registry = $this->app->make(AgentToolRegistry::class);
 
+        // Idempotent: register() runs once per application, but a host that
+        // still delivers the event must not double-register and trip the
+        // duplicate-name guard.
+        if ($registry->all()->isNotEmpty()) {
+            return;
+        }
+
         $toolClasses = [
             Mcp\Tools\Agent\Brain\BrainRemember::class,
             Mcp\Tools\Agent\Brain\BrainRecall::class,
diff --git a/php/Mcp/Console/McpAgentServerCommand.php b/php/Mcp/Console/McpAgentServerCommand.php
index 1bc72a29..56609b96 100644
--- a/php/Mcp/Console/McpAgentServerCommand.php
+++ b/php/Mcp/Console/McpAgentServerCommand.php
@@ -8,8 +8,8 @@
 
 use Core\Mod\Agentic\Mcp\Services\McpQuotaService;
 use Core\Mod\Agentic\Mcp\Services\QueryAuditService;
-use Core\Mod\Agentic\Mcp\Services\ToolRegistry;
 use Core\Mod\Agentic\Services\AgentResourceRegistry;
+use Core\Mod\Agentic\Services\AgentToolRegistry;
 use Illuminate\Console\Command;
 use InvalidArgumentException;
 use JsonException;
@@ -35,7 +35,7 @@ class McpAgentServerCommand extends Command
      * $exitCode = $this->handle($toolRegistry, $quotaService, $queryAuditService);
      */
     public function handle(
-        ToolRegistry $toolRegistry,
+        AgentToolRegistry $toolRegistry,
         McpQuotaService $quotaService,
         QueryAuditService $queryAuditService,
         AgentResourceRegistry $resourceRegistry,
@@ -118,7 +118,7 @@ private function streamPath(string $variable, string $default): string
      */
     private function processPayload(
         string $payload,
-        ToolRegistry $toolRegistry,
+        AgentToolRegistry $toolRegistry,
         McpQuotaService $quotaService,
         QueryAuditService $queryAuditService,
         AgentResourceRegistry $resourceRegistry,
@@ -174,7 +174,7 @@ private function processPayload(
      */
     private function processRequest(
         array $request,
-        ToolRegistry $toolRegistry,
+        AgentToolRegistry $toolRegistry,
         McpQuotaService $quotaService,
         QueryAuditService $queryAuditService,
         AgentResourceRegistry $resourceRegistry,
@@ -262,7 +262,7 @@ private function processRequest(
     private function handleToolCall(
         array $params,
         mixed $id,
-        ToolRegistry $toolRegistry,
+        AgentToolRegistry $toolRegistry,
         McpQuotaService $quotaService,
         QueryAuditService $queryAuditService,
     ): array {
diff --git a/php/Mcp/Services/ToolDependencyService.php b/php/Mcp/Services/ToolDependencyService.php
index 7dd36cee..a60461d9 100644
--- a/php/Mcp/Services/ToolDependencyService.php
+++ b/php/Mcp/Services/ToolDependencyService.php
@@ -8,6 +8,7 @@
 
 use Carbon\CarbonImmutable;
 use Core\Mcp\Dependencies\ToolDependency;
+use Core\Mod\Agentic\Services\AgentToolRegistry;
 use Illuminate\Container\Container;
 use InvalidArgumentException;
 use RuntimeException;
@@ -25,7 +26,7 @@ final class ToolDependencyService
     private array $toolCalls = [];
 
     public function __construct(
-        private ?ToolRegistry $registry = null,
+        private ?AgentToolRegistry $registry = null,
         private readonly ?Container $container = null,
     ) {
         $this->registry ??= $this->resolveRegistry();
@@ -105,15 +106,15 @@ public function calledTools(string $sessionId): array
         return array_keys($this->toolCalls[$sessionId] ?? []);
     }
 
-    private function resolveRegistry(): ?ToolRegistry
+    private function resolveRegistry(): ?AgentToolRegistry
     {
         $container = $this->container ?? Container::getInstance();
 
-        if (! $container instanceof Container || ! $container->bound(ToolRegistry::class)) {
+        if (! $container instanceof Container || ! $container->bound(AgentToolRegistry::class)) {
             return null;
         }
 
-        return $container->make(ToolRegistry::class);
+        return $container->make(AgentToolRegistry::class);
     }
 
     /**
diff --git a/php/Mcp/Services/ToolRegistry.php b/php/Mcp/Services/ToolRegistry.php
deleted file mode 100644
index 36690baa..00000000
--- a/php/Mcp/Services/ToolRegistry.php
+++ /dev/null
@@ -1,88 +0,0 @@
-<?php
-
-// SPDX-License-Identifier: EUPL-1.2
-
-declare(strict_types=1);
-
-namespace Core\Mod\Agentic\Mcp\Services;
-
-use Core\Mod\Agentic\Mcp\Data\ToolMetadata;
-use Illuminate\Container\Container;
-use InvalidArgumentException;
-
-final class ToolRegistry
-{
-    /**
-     * @var array<string, ToolMetadata>
-     */
-    private array $tools = [];
-
-    public function __construct(
-        private readonly ?Container $container = null,
-    ) {}
-
-    public static function registerSingleton(Container $container): self
-    {
-        if (! $container->bound(self::class)) {
-            $container->singleton(self::class, fn (Container $app): self => new self($app));
-        }
-
-        return $container->make(self::class);
-    }
-
-    public function register(mixed $tool): ToolMetadata
-    {
-        $metadata = ToolMetadata::from($tool);
-
-        if (isset($this->tools[$metadata->name])) {
-            throw new InvalidArgumentException(sprintf(
-                'Tool [%s] is already registered.',
-                $metadata->name,
-            ));
-        }
-
-        $this->tools[$metadata->name] = $metadata;
-
-        return $metadata;
-    }
-
-    public function resolve(string $name): ?ToolMetadata
-    {
-        return $this->tools[$name] ?? null;
-    }
-
-    /**
-     * @return array<int, ToolMetadata>
-     */
-    public function listTools(): array
-    {
-        return array_values($this->tools);
-    }
-
-    /**
-     * @return array<string, array<int, string>>
-     */
-    public function buildDependencyGraph(): array
-    {
-        $graph = [];
-
-        foreach ($this->tools as $name => $tool) {
-            $graph[$name] = $tool->dependencyIdentifiers();
-        }
-
-        return $graph;
-    }
-
-    public function call(string $name, array $arguments = [], array $context = []): mixed
-    {
-        $tool = $this->resolve($name);
-        if ($tool === null) {
-            throw new InvalidArgumentException(sprintf(
-                'Unknown tool [%s].',
-                $name,
-            ));
-        }
-
-        return $tool->call($arguments, $context);
-    }
-}
diff --git a/php/Services/AgentToolRegistry.php b/php/Services/AgentToolRegistry.php
index 0dbbcd3d..7a0d2db1 100644
--- a/php/Services/AgentToolRegistry.php
+++ b/php/Services/AgentToolRegistry.php
@@ -7,6 +7,7 @@
 use Core\Api\Models\ApiKey;
 use Core\Mcp\Dependencies\HasDependencies;
 use Core\Mcp\Exceptions\MissingDependencyException;
+use Core\Mod\Agentic\Mcp\Data\ToolMetadata;
 use Core\Mod\Agentic\Mcp\Services\ToolDependencyService;
 use Core\Mod\Agentic\Mcp\Tools\Agent\Contracts\AgentToolInterface;
 use Illuminate\Support\Collection;
@@ -37,6 +38,16 @@ class AgentToolRegistry
      */
     public function register(AgentToolInterface $tool): self
     {
+        // Absorbed from the registry this replaced: two tools claiming one name
+        // is a wiring mistake, and silently keeping the last one registered
+        // means the MCP surface serves whichever file happened to load second.
+        if (isset($this->tools[$tool->name()])) {
+            throw new \InvalidArgumentException(sprintf(
+                'Tool [%s] is already registered.',
+                $tool->name(),
+            ));
+        }
+
         $this->tools[$tool->name()] = $tool;
 
         // Auto-register dependencies if tool declares them
@@ -363,4 +374,81 @@ private function enforceAndRecordRateLimit(ApiKey $apiKey, string $toolName): vo
             );
         }
     }
+
+    /**
+     * Every registered tool as MCP metadata.
+     *
+     * Absorbed from Mcp\Services\ToolRegistry, which the stdio agent server
+     * read while Boot filled this registry instead — so the server listed
+     * nothing. One registry now, so there is one answer to "what tools exist".
+     *
+     * @return array<int, ToolMetadata>
+     *
+     * @example
+     * $registry->listTools();
+     */
+    public function listTools(): array
+    {
+        return array_values(array_map(
+            static fn (AgentToolInterface $tool): ToolMetadata => ToolMetadata::from($tool),
+            $this->tools,
+        ));
+    }
+
+    /**
+     * Resolve one tool as MCP metadata, or null when it is not registered.
+     *
+     * @example
+     * $registry->resolve('plan_create');
+     */
+    public function resolve(string $name): ?ToolMetadata
+    {
+        $tool = $this->tools[$name] ?? null;
+
+        return $tool === null ? null : ToolMetadata::from($tool);
+    }
+
+    /**
+     * Map each tool name to the identifiers it declares as dependencies.
+     *
+     * @return array<string, array<int, string>>
+     *
+     * @example
+     * $registry->buildDependencyGraph();
+     */
+    public function buildDependencyGraph(): array
+    {
+        $graph = [];
+
+        foreach ($this->tools as $name => $tool) {
+            $graph[$name] = ToolMetadata::from($tool)->dependencyIdentifiers();
+        }
+
+        return $graph;
+    }
+
+    /**
+     * Invoke a tool directly, without the permission and dependency checks
+     * execute() applies.
+     *
+     * Kept distinct from execute() rather than merged into it: the stdio
+     * transport has no API key to check scopes against and runs its own quota
+     * and audit passes around this call, whereas execute() is the governed
+     * path used where an ApiKey is present.
+     *
+     * @throws \InvalidArgumentException If the tool is not registered
+     *
+     * @example
+     * $registry->call('plan_list', [], ['workspace_id' => 'ws-1']);
+     */
+    public function call(string $name, array $arguments = [], array $context = []): mixed
+    {
+        $tool = $this->get($name);
+
+        if (! $tool) {
+            throw new \InvalidArgumentException(sprintf('Unknown tool [%s].', $name));
+        }
+
+        return $tool->handle($arguments, $context);
+    }
 }
diff --git a/php/tests/Feature/Mcp/Console/McpAgentServerCommandTest.php b/php/tests/Feature/Mcp/Console/McpAgentServerCommandTest.php
index cf0a9684..1968a473 100644
--- a/php/tests/Feature/Mcp/Console/McpAgentServerCommandTest.php
+++ b/php/tests/Feature/Mcp/Console/McpAgentServerCommandTest.php
@@ -6,8 +6,9 @@
 
 use Core\Mod\Agentic\Mcp\Console\McpAgentServerCommand;
 use Core\Mod\Agentic\Mcp\Services\McpQuotaService;
-use Core\Mod\Agentic\Mcp\Services\ToolRegistry;
+use Core\Mod\Agentic\Mcp\Tools\Agent\Contracts\AgentToolInterface;
 use Core\Mod\Agentic\Models\AgentPlan;
+use Core\Mod\Agentic\Services\AgentToolRegistry;
 use Illuminate\Contracts\Console\Kernel;
 use Illuminate\Database\Schema\Blueprint;
 use Illuminate\Support\Facades\Artisan;
@@ -19,7 +20,7 @@
         $this->app->make(McpAgentServerCommand::class),
     );
 
-    ToolRegistry::registerSingleton($this->app)->register(new class
+    $this->app->make(AgentToolRegistry::class)->register(new class implements AgentToolInterface
     {
         public function name(): string
         {
@@ -44,6 +45,16 @@ public function handle(array $arguments, array $context = []): array
                 'value' => $arguments['value'] ?? null,
             ];
         }
+
+        public function requiredScopes(): array
+        {
+            return ['read'];
+        }
+
+        public function category(): string
+        {
+            return 'testing';
+        }
     });
 
     Schema::dropIfExists('mcp_audit_entries');
diff --git a/php/tests/Feature/Mcp/Middleware/McpAuthenticateTest.php b/php/tests/Feature/Mcp/Middleware/McpAuthenticateTest.php
index fa4a2e91..b9d63d73 100644
--- a/php/tests/Feature/Mcp/Middleware/McpAuthenticateTest.php
+++ b/php/tests/Feature/Mcp/Middleware/McpAuthenticateTest.php
@@ -6,8 +6,8 @@
 
 use Core\Mod\Agentic\Mcp\Services\McpQuotaService;
 use Core\Mod\Agentic\Mcp\Services\ToolDependencyService;
-use Core\Mod\Agentic\Mcp\Services\ToolRegistry;
 use Core\Mod\Agentic\Services\AgentApiKeyService;
+use Core\Mod\Agentic\Services\AgentToolRegistry;
 use Core\Mod\Agentic\Website\Mcp\Middleware\CheckMcpQuota;
 use Core\Mod\Agentic\Website\Mcp\Middleware\McpApiKeyAuth;
 use Core\Mod\Agentic\Website\Mcp\Middleware\McpAuthenticate;
@@ -15,6 +15,7 @@
 use Core\Mod\Agentic\Website\Mcp\Middleware\ValidateWorkspaceContext;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Cache;
+use Symfony\Component\HttpFoundation\Response;
 
 beforeEach(function (): void {
     Cache::flush();
@@ -26,7 +27,7 @@
     $workspace = createWorkspace();
     $apiKey = createApiKey($workspace, 'Combined Auth Key');
 
-    $registry = new ToolRegistry;
+    $registry = new AgentToolRegistry;
     $registry->register(mcpMiddlewareToolFixture('plan_list', [
         ['type' => 'context_exists', 'key' => 'workspace_id', 'message' => 'Workspace context required.'],
     ]));
@@ -72,7 +73,7 @@
         new McpApiKeyAuth(app(AgentApiKeyService::class)),
         new CheckMcpQuota($quotaService),
         new ValidateWorkspaceContext,
-        new ValidateToolDependencies(new ToolDependencyService(new ToolRegistry, $this->app)),
+        new ValidateToolDependencies(new ToolDependencyService(new AgentToolRegistry, $this->app)),
     );
 
     $request = Request::create('/api/v1/mcp/tools/call', 'POST', [
@@ -93,7 +94,7 @@
 test('McpAuthenticate_handle_Ugly_bubbles_missing_workspace_context_failures_from_the_validation_stage', function (): void {
     $brokenAuth = new class(app(AgentApiKeyService::class)) extends McpApiKeyAuth
     {
-        public function handle(Request $request, Closure $next): \Symfony\Component\HttpFoundation\Response
+        public function handle(Request $request, Closure $next): Response
         {
             return $next($request);
         }
@@ -103,7 +104,7 @@ public function handle(Request $request, Closure $next): \Symfony\Component\Http
         $brokenAuth,
         new CheckMcpQuota(new McpQuotaService),
         new ValidateWorkspaceContext,
-        new ValidateToolDependencies(new ToolDependencyService(new ToolRegistry, $this->app)),
+        new ValidateToolDependencies(new ToolDependencyService(new AgentToolRegistry, $this->app)),
     );
 
     $request = Request::create('/api/v1/mcp/tools/call', 'POST', [
diff --git a/php/tests/Feature/Mcp/Middleware/ValidateToolDependenciesTest.php b/php/tests/Feature/Mcp/Middleware/ValidateToolDependenciesTest.php
index e3bcdc22..c0451e00 100644
--- a/php/tests/Feature/Mcp/Middleware/ValidateToolDependenciesTest.php
+++ b/php/tests/Feature/Mcp/Middleware/ValidateToolDependenciesTest.php
@@ -5,13 +5,14 @@
 declare(strict_types=1);
 
 use Core\Mod\Agentic\Mcp\Services\ToolDependencyService;
-use Core\Mod\Agentic\Mcp\Services\ToolRegistry;
+use Core\Mod\Agentic\Mcp\Tools\Agent\Contracts\AgentToolInterface;
+use Core\Mod\Agentic\Services\AgentToolRegistry;
 use Core\Mod\Agentic\Website\Mcp\Middleware\ValidateToolDependencies;
 use Illuminate\Http\Request;
 
 function mcpMiddlewareToolFixture(string $name, array $dependencies = []): object
 {
-    return new class($name, $dependencies)
+    return new class($name, $dependencies) implements AgentToolInterface
     {
         public function __construct(
             private readonly string $toolName,
@@ -46,11 +47,21 @@ public function handle(array $arguments, array $context = []): array
                 'tool' => $this->toolName,
             ];
         }
+
+        public function requiredScopes(): array
+        {
+            return ['read'];
+        }
+
+        public function category(): string
+        {
+            return 'testing';
+        }
     };
 }
 
 test('ValidateToolDependencies_handle_Good_validates_json_rpc_tool_calls_and_records_successful_execution', function (): void {
-    $registry = new ToolRegistry;
+    $registry = new AgentToolRegistry;
     $registry->register(mcpMiddlewareToolFixture('session_start'));
     $registry->register(mcpMiddlewareToolFixture('report_generate', [
         ['type' => 'tool', 'tool' => 'session_start', 'message' => 'Start session first.'],
@@ -80,7 +91,7 @@ public function handle(array $arguments, array $context = []): array
 });
 
 test('ValidateToolDependencies_handle_Bad_returns_conflict_when_required_dependencies_are_missing', function (): void {
-    $registry = new ToolRegistry;
+    $registry = new AgentToolRegistry;
     $registry->register(mcpMiddlewareToolFixture('plan_list', [
         ['type' => 'context_exists', 'key' => 'workspace_id', 'message' => 'Workspace context required.'],
     ]));
@@ -101,7 +112,7 @@ public function handle(array $arguments, array $context = []): array
 });
 
 test('ValidateToolDependencies_handle_Ugly_converts_circular_dependency_failures_into_conflict_responses', function (): void {
-    $registry = new ToolRegistry;
+    $registry = new AgentToolRegistry;
     $registry->register(mcpMiddlewareToolFixture('tool_alpha', [
         ['type' => 'tool', 'tool' => 'tool_bravo', 'message' => 'tool_bravo is required.'],
     ]));
diff --git a/php/tests/Feature/Mcp/Services/AgentToolRegistryBootTest.php b/php/tests/Feature/Mcp/Services/AgentToolRegistryBootTest.php
new file mode 100644
index 00000000..60cb26ba
--- /dev/null
+++ b/php/tests/Feature/Mcp/Services/AgentToolRegistryBootTest.php
@@ -0,0 +1,72 @@
+<?php
+
+// SPDX-License-Identifier: EUPL-1.2
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Tests\Feature\Mcp\Services;
+
+use Core\Mod\Agentic\Mcp\Tools\Agent\Brain\BrainRemember;
+use Core\Mod\Agentic\Services\AgentToolRegistry;
+use Tests\TestCase;
+
+/**
+ * Guards the outage this suite could not see for as long as it existed.
+ *
+ * Three separate faults kept the agent MCP server serving nothing, and a green
+ * suite never noticed any of them:
+ *
+ *   1. every tool class was fatal on load, because AgentTool used a trait this
+ *      repo did not contain;
+ *   2. Boot filled the registry from a $listens event that ModuleScanner only
+ *      wires from app/Core|Mod|Website, so it never fired under vendor/;
+ *   3. the stdio server read a second, never-bound registry class entirely.
+ *
+ * McpAgentServerCommandTest passed throughout, because its beforeEach
+ * registered a tool of its own — it supplied exactly what production lacked.
+ * So these assert on a plain booted application and register nothing.
+ */
+class AgentToolRegistryBootTest extends TestCase
+{
+    public function test_tools_good_construct_at_all(): void
+    {
+        // The floor. For months this line raised
+        // Trait "Core\Mcp\Tools\Concerns\ValidatesDependencies" not found.
+        $this->assertSame('brain_remember', (new BrainRemember)->name());
+    }
+
+    public function test_registry_good_is_filled_by_boot_with_no_test_supplied_tools(): void
+    {
+        $registry = $this->app->make(AgentToolRegistry::class);
+
+        $this->assertNotEmpty(
+            $registry->all(),
+            'Boot registered no tools — the agent MCP server would advertise nothing.',
+        );
+    }
+
+    public function test_registry_good_exposes_those_tools_on_the_path_the_server_reads(): void
+    {
+        // listTools() is what McpAgentServerCommand answers tools/list from.
+        // Filled-but-unreadable was the shape of fault 3.
+        $names = array_map(
+            static fn ($tool): string => $tool->name,
+            $this->app->make(AgentToolRegistry::class)->listTools(),
+        );
+
+        $this->assertNotEmpty($names);
+        $this->assertContains('plan_create', $names);
+        $this->assertContains('session_start', $names);
+        $this->assertContains('brain_remember', $names);
+    }
+
+    public function test_registry_good_is_one_shared_instance(): void
+    {
+        // A non-singleton hands the command a fresh empty registry, which is
+        // how the registry it used to read failed even once something filled it.
+        $this->assertSame(
+            $this->app->make(AgentToolRegistry::class),
+            $this->app->make(AgentToolRegistry::class),
+        );
+    }
+}
diff --git a/php/tests/Feature/Mcp/Services/ToolDependencyServiceTest.php b/php/tests/Feature/Mcp/Services/ToolDependencyServiceTest.php
index 57b4c4d6..62ae54ee 100644
--- a/php/tests/Feature/Mcp/Services/ToolDependencyServiceTest.php
+++ b/php/tests/Feature/Mcp/Services/ToolDependencyServiceTest.php
@@ -5,24 +5,69 @@
 declare(strict_types=1);
 
 use Core\Mod\Agentic\Mcp\Services\ToolDependencyService;
-use Core\Mod\Agentic\Mcp\Services\ToolRegistry;
+use Core\Mod\Agentic\Mcp\Tools\Agent\Contracts\AgentToolInterface;
+use Core\Mod\Agentic\Services\AgentToolRegistry;
 
-function mcpDependencyToolFixture(string $name, array $dependencies = []): array
+/**
+ * A registrable tool declaring the given dependencies.
+ *
+ * An AgentToolInterface, not the loose array payload this used to build: the
+ * registry these tests exercise is now the typed one, and a metadata array is
+ * no longer a thing that can be registered. The dependency rows stay arrays,
+ * which is what ToolDependencyService normalises.
+ */
+function mcpDependencyToolFixture(string $name, array $dependencies = []): AgentToolInterface
 {
-    return [
-        'name' => $name,
-        'description' => 'Fixture tool',
-        'dependencies' => $dependencies,
-        'handler' => static fn (array $arguments = [], array $context = []): array => [
-            'arguments' => $arguments,
-            'context' => $context,
-            'tool' => $name,
-        ],
-    ];
+    return new class($name, $dependencies) implements AgentToolInterface
+    {
+        public function __construct(
+            private readonly string $toolName,
+            private readonly array $toolDependencies,
+        ) {}
+
+        public function name(): string
+        {
+            return $this->toolName;
+        }
+
+        public function description(): string
+        {
+            return 'Fixture tool';
+        }
+
+        public function inputSchema(): array
+        {
+            return ['type' => 'object'];
+        }
+
+        public function dependencies(): array
+        {
+            return $this->toolDependencies;
+        }
+
+        public function handle(array $args, array $context = []): array
+        {
+            return [
+                'arguments' => $args,
+                'context' => $context,
+                'tool' => $this->toolName,
+            ];
+        }
+
+        public function requiredScopes(): array
+        {
+            return ['read'];
+        }
+
+        public function category(): string
+        {
+            return 'testing';
+        }
+    };
 }
 
 test('ToolDependencyService_validateDependencies_Good_walks_transitive_tool_graphs_before_execution', function (): void {
-    $registry = new ToolRegistry;
+    $registry = new AgentToolRegistry;
 
     $registry->register(mcpDependencyToolFixture('session_start'));
     $registry->register(mcpDependencyToolFixture('session_log', [
@@ -48,7 +93,7 @@ function mcpDependencyToolFixture(string $name, array $dependencies = []): array
 });
 
 test('ToolDependencyService_validateDependencies_Bad_reports_missing_context_requirements', function (): void {
-    $registry = new ToolRegistry;
+    $registry = new AgentToolRegistry;
     $registry->register(mcpDependencyToolFixture('plan_list', [
         ['type' => 'context_exists', 'key' => 'workspace_id', 'message' => 'Workspace context required.'],
     ]));
@@ -58,7 +103,7 @@ function mcpDependencyToolFixture(string $name, array $dependencies = []): array
 })->throws(RuntimeException::class, 'Workspace context required.');
 
 test('ToolDependencyService_validateDependencies_Ugly_detects_circular_tool_dependencies', function (): void {
-    $registry = new ToolRegistry;
+    $registry = new AgentToolRegistry;
 
     $registry->register(mcpDependencyToolFixture('tool_alpha', [
         ['type' => 'tool', 'tool' => 'tool_bravo', 'message' => 'tool_bravo is required.'],
diff --git a/php/tests/Feature/Mcp/Services/ToolRegistryTest.php b/php/tests/Feature/Mcp/Services/ToolRegistryTest.php
index b978942b..3d154020 100644
--- a/php/tests/Feature/Mcp/Services/ToolRegistryTest.php
+++ b/php/tests/Feature/Mcp/Services/ToolRegistryTest.php
@@ -4,11 +4,12 @@
 
 declare(strict_types=1);
 
-use Core\Mod\Agentic\Mcp\Services\ToolRegistry;
+use Core\Mod\Agentic\Mcp\Tools\Agent\Contracts\AgentToolInterface;
+use Core\Mod\Agentic\Services\AgentToolRegistry;
 
 function mcpToolRegistryFixture(string $name, array $dependencies = []): object
 {
-    return new class($name, $dependencies)
+    return new class($name, $dependencies) implements AgentToolInterface
     {
         public function __construct(
             private readonly string $toolName,
@@ -43,11 +44,24 @@ public function handle(array $arguments, array $context = []): array
                 'tool' => $this->toolName,
             ];
         }
+
+        public function requiredScopes(): array
+        {
+            return ['read'];
+        }
+
+        public function category(): string
+        {
+            return 'testing';
+        }
     };
 }
 
-test('ToolRegistry_register_resolve_listTools_buildDependencyGraph_Good_binds_the_registry_as_a_singleton', function (): void {
-    $registry = ToolRegistry::registerSingleton($this->app);
+test('AgentToolRegistry_register_resolve_listTools_buildDependencyGraph_Good_absorbs_the_mcp_surface', function (): void {
+    // A fresh registry, not the container's: Boot now fills the singleton with
+    // the forty real tools, so registering session_start into it would collide
+    // with the real one and listTools() would return forty-two.
+    $registry = new AgentToolRegistry;
 
     $registry->register(mcpToolRegistryFixture('session_start'));
     $registry->register(mcpToolRegistryFixture('report_generate', [
@@ -55,10 +69,10 @@ public function handle(array $arguments, array $context = []): array
         ['type' => 'context_exists', 'key' => 'workspace_id'],
     ]));
 
-    $resolved = $this->app->make(ToolRegistry::class);
     $graph = $registry->buildDependencyGraph();
 
-    expect($resolved)->toBe($registry)
+    expect($this->app->make(AgentToolRegistry::class))
+        ->toBe($this->app->make(AgentToolRegistry::class))
         ->and($registry->resolve('report_generate')?->name)->toBe('report_generate')
         ->and(array_map(
             static fn ($tool): string => $tool->name,
@@ -76,18 +90,9 @@ public function handle(array $arguments, array $context = []): array
         ]);
 });
 
-test('ToolRegistry_register_Bad_rejects_duplicate_tool_names', function (): void {
-    $registry = new ToolRegistry;
+test('AgentToolRegistry_register_Bad_rejects_duplicate_tool_names', function (): void {
+    $registry = new AgentToolRegistry;
 
     $registry->register(mcpToolRegistryFixture('session_start'));
     $registry->register(mcpToolRegistryFixture('session_start'));
 })->throws(InvalidArgumentException::class, 'Tool [session_start] is already registered.');
-
-test('ToolRegistry_register_Ugly_rejects_payloads_without_a_callable_handler', function (): void {
-    $registry = new ToolRegistry;
-
-    $registry->register([
-        'name' => 'broken_tool',
-        'description' => 'No callable handler',
-    ]);
-})->throws(InvalidArgumentException::class, 'A callable handler is required');