Fix route coverage parameter validation for sessionMetadataValue

Add symmetric validation to reject sessionMetadataValue when provided
without sessionMetadataName. Previously, the tool silently ignored
sessionMetadataValue in this scenario, causing users to receive
unfiltered results without any indication of the misconfiguration.

Changes:
- Added validation check rejecting null/empty sessionMetadataName with
  non-null sessionMetadataValue (mirrors existing reverse check)
- Updated @tool description with explicit note about parameter dependency
- Updated JavaDoc for both parameters stating "Must be provided with..."
- Updated @throws documentation to cover both validation directions

Testing:
- Added testGetRouteCoverage_SessionMetadataValue_WithoutName() test
- Added testGetRouteCoverage_SessionMetadataValue_WithEmptyName() test
- All 327 tests passing (26 RouteCoverageService tests)

Users now receive immediate, clear error messages instead of silently
incorrect results. AI models consuming the tool see explicit
documentation about the parameter dependency.

Addresses mcp-rlc.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: ChrisEdwards

src/main/java/com/contrast/labs/ai/mcp/contrast/RouteCoverageService.java

@@ -45,14 +45,14 @@ public class RouteCoverageService {
    *
    * @param appId Required - The application ID to retrieve route coverage for
    * @param sessionMetadataName Optional - Filter by session metadata field name (e.g., "branch").
-   *     Empty strings are treated as null (no filter).
+   *     Must be provided with sessionMetadataValue. Empty strings are treated as null (no filter).
    * @param sessionMetadataValue Optional - Filter by session metadata field value (e.g., "main").
-   *     Required if sessionMetadataName is provided. Empty strings are treated as null.
+   *     Must be provided with sessionMetadataName. Empty strings are treated as null.
    * @param useLatestSession Optional - If true, only return routes from the latest session
    * @return RouteCoverageResponse containing route coverage data with details for each route
    * @throws IOException If an error occurs while retrieving data from Contrast
    * @throws IllegalArgumentException If sessionMetadataName is provided without
-   *     sessionMetadataValue
+   *     sessionMetadataValue, or if sessionMetadataValue is provided without sessionMetadataName
    */
   @Tool(
       name = "get_route_coverage",
@@ -61,8 +61,9 @@ public class RouteCoverageService {
               + " not exercised) or EXERCISED (received HTTP traffic). All filter parameters are"
               + " truly optional - if none provided (null or empty strings), returns all routes"
               + " across all sessions. Parameters: appId (required), sessionMetadataName"
-              + " (optional), sessionMetadataValue (optional - required if sessionMetadataName"
-              + " provided), useLatestSession (optional).")
+              + " (optional), sessionMetadataValue (optional). NOTE: sessionMetadataName and"
+              + " sessionMetadataValue must be provided together or both omitted - providing"
+              + " only one will result in an error. useLatestSession (optional).")
   public RouteCoverageResponse getRouteCoverage(
       String appId,
       String sessionMetadataName,
@@ -79,6 +80,13 @@ public RouteCoverageResponse getRouteCoverage(
       throw new IllegalArgumentException(errorMsg);
     }
 
+    // Validate sessionMetadataValue requires sessionMetadataName
+    if (StringUtils.hasText(sessionMetadataValue) && !StringUtils.hasText(sessionMetadataName)) {
+      var errorMsg = "sessionMetadataName is required when sessionMetadataValue is provided";
+      log.error(errorMsg);
+      throw new IllegalArgumentException(errorMsg);
+    }
+
     // Initialize SDK
     var contrastSDK =
         SDKHelper.getSDK(hostName, apiKey, serviceKey, userName, httpProxyHost, httpProxyPort);

src/test/java/com/contrast/labs/ai/mcp/contrast/RouteCoverageServiceTest.java

@@ -311,6 +311,39 @@ void testGetRouteCoverage_SessionMetadataFilter_EmptyValue() throws Exception {
     verify(mockSDKExtension, never()).getRouteCoverage(anyString(), anyString(), any());
   }
 
+  @Test
+  void testGetRouteCoverage_SessionMetadataValue_WithoutName() throws Exception {
+    // Test validation with sessionMetadataValue provided but sessionMetadataName null (MCP-RLC)
+    // Act & Assert
+    assertThatThrownBy(
+            () -> {
+              routeCoverageService.getRouteCoverage(TEST_APP_ID, null, TEST_METADATA_VALUE, null);
+            })
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessageContaining(
+            "sessionMetadataName is required when sessionMetadataValue is provided");
+
+    // Verify SDK was never called
+    verify(mockSDKExtension, never()).getRouteCoverage(anyString(), anyString(), any());
+  }
+
+  @Test
+  void testGetRouteCoverage_SessionMetadataValue_WithEmptyName() throws Exception {
+    // Test validation with empty string sessionMetadataName and sessionMetadataValue provided
+    // (MCP-RLC)
+    // Act & Assert
+    assertThatThrownBy(
+            () -> {
+              routeCoverageService.getRouteCoverage(TEST_APP_ID, "", TEST_METADATA_VALUE, null);
+            })
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessageContaining(
+            "sessionMetadataName is required when sessionMetadataValue is provided");
+
+    // Verify SDK was never called
+    verify(mockSDKExtension, never()).getRouteCoverage(anyString(), anyString(), any());
+  }
+
   // ========== Test Case 3: Latest Session Filter ==========
 
   @Test