Exclude Auto injected client logger from generated input-schema

Author: Adebayo120

src/Capability/Discovery/SchemaGenerator.php

@@ -409,6 +409,10 @@ private function parseParametersInfo(\ReflectionMethod|\ReflectionFunction $refl
         $parametersInfo = [];
 
         foreach ($reflection->getParameters() as $rp) {
+            if ($this->isAutoInjectedParameter($rp)) {
+                continue;
+            }
+
             $paramName = $rp->getName();
             $paramTag = $paramTags['$'.$paramName] ?? null;
 
@@ -784,4 +788,25 @@ private function mapSimpleTypeToJsonSchema(string $type): string
             default => \in_array(strtolower($type), ['datetime', 'datetimeinterface']) ? 'string' : 'object',
         };
     }
+
+    /**
+     * Determines if a parameter was auto-injected and should be excluded from schema generation.
+     *
+     * Parameters that are auto-injected by the framework (like McpLogger) should not appear
+     * in the tool schema since they're not provided by the client.
+     */
+    private function isAutoInjectedParameter(\ReflectionParameter $parameter): bool
+    {
+        $type = $parameter->getType();
+
+        if (!$type instanceof \ReflectionNamedType) {
+            return false;
+        }
+
+        $typeName = $type->getName();
+
+        // Auto-inject for McpLogger or LoggerInterface types
+        return 'Mcp\\Capability\\Logger\\McpLogger' === $typeName 
+            || 'Psr\\Log\\LoggerInterface' === $typeName;
+    }
 }

tests/Inspector/snapshots/StdioCalculatorExampleTest-tools_list.json

@@ -14,10 +14,6 @@
             "type": "number",
             "description": "the second operand"
           },
-          "logger": {
-            "type": "object",
-            "description": "Auto-injected MCP logger"
-          },
           "operation": {
             "type": "string",
             "description": "the operation ('add', 'subtract', 'multiply', 'divide')"
@@ -26,8 +22,7 @@
         "required": [
           "a",
           "b",
-          "operation",
-          "logger"
+          "operation"
         ]
       }
     },
@@ -37,10 +32,6 @@
       "inputSchema": {
         "type": "object",
         "properties": {
-          "logger": {
-            "type": "object",
-            "description": "Auto-injected MCP logger"
-          },
           "setting": {
             "type": "string",
             "description": "the setting key ('precision' or 'allow_negative')"
@@ -51,8 +42,7 @@
         },
         "required": [
           "setting",
-          "value",
-          "logger"
+          "value"
         ]
       }
     }

tests/Unit/Capability/Discovery/SchemaGeneratorFixture.php

@@ -412,4 +412,15 @@ public function parameterSchemaInferredType(
         $inferredParam,
     ): void {
     }
+
+    /**
+     * Method with McpLogger that should be excluded from schema.
+     *
+     * @param string $message The message to process
+     * @param \Mcp\Capability\Logger\McpLogger $logger Auto-injected logger
+     */
+    public function withMcpLogger(string $message, \Mcp\Capability\Logger\McpLogger $logger): string
+    {
+        return $message;
+    }
 }

tests/Unit/Capability/Discovery/SchemaGeneratorTest.php

@@ -327,4 +327,20 @@ public function testInfersParameterTypeAsAnyIfOnlyConstraintsAreGiven()
         $this->assertEquals(['description' => 'Some parameter', 'minLength' => 3], $schema['properties']['inferredParam']);
         $this->assertEquals(['inferredParam'], $schema['required']);
     }
+
+    public function testExcludesMcpLoggerFromSchema()
+    {
+        $method = new \ReflectionMethod(SchemaGeneratorFixture::class, 'withMcpLogger');
+        $schema = $this->schemaGenerator->generate($method);
+        
+        // Should include the message parameter
+        $this->assertArrayHasKey('message', $schema['properties']);
+        $this->assertEquals(['type' => 'string', 'description' => 'The message to process'], $schema['properties']['message']);
+        
+        // Should NOT include the logger parameter
+        $this->assertArrayNotHasKey('logger', $schema['properties']);
+        
+        // Required array should only contain client parameters
+        $this->assertEquals(['message'], $schema['required']);
+    }
 }