📝 Update Information

Primitive Details

• Type: Tool
• Name: All CLI tools registered via registerCLITool + codeql_resolve_queries integration test
• Update Category: Bug Fix

⚠️ CRITICAL: PR SCOPE VALIDATION

✅ ALLOWED FILES:

• Server implementation files (server/src/**/*.ts)
• Modified registration files (server/src/tools/*.ts)
• Updated test files (server/test/**/*.ts)
• Client integration test runner (client/src/lib/integration-test-runner.js)

🚫 FORBIDDEN FILES: None included.

🛑 MANDATORY PR VALIDATION CHECKLIST

• ONLY server implementation files are included
• NO temporary or output files are included
• NO unrelated configuration files are included
• ALL existing tests continue to pass
• NEW functionality is properly tested

• Impact Scope: Extensive — affects all 24 CLI tool registrations and one integration test

Update Metadata

• Breaking Changes: No
• API Compatibility: Maintained
• Performance Impact: Neutral

🎯 Changes Description

Current Behavior

Server crashes at startup on every OS:

Error: Tool codeql_bqrs_decode expected a Zod schema or ToolAnnotations,
       but received an unrecognized object
    at McpServer.tool (...)
    at registerCLITool (...)

The codeql_resolve_queries/resolve_queries integration test sends params.path which doesn't exist in the tool schema, causing validation rejection.

Updated Behavior

Server starts successfully. All 24 CLI tools register without error. The codeql_resolve_queries integration test uses the correct parameter name directory.

Motivation

buildEnhancedToolSchema() returns a ZodEffects object (via .passthrough().transform()). The MCP SDK's tool() argument parser calls isZodRawShapeCompat() which returns false for any Zod schema instance (it checks isZodSchemaInstance() first). The object then falls into the ToolAnnotations branch, which rejects it because Zod internals contain nested objects.

registerTool() bypasses this argument-parsing entirely — it passes inputSchema directly to getZodSchemaObject(), which correctly recognizes ZodEffects as a valid schema instance.

🔄 Before vs. After Comparison

Functionality Changes

// BEFORE: tool() rejects ZodEffects via isZodRawShapeCompat() → throws
server.tool(
  name,
  description,
  enhancedSchema as unknown as Record<string, z.ZodTypeAny>,
  async (params) => { /* ... */ }
);

// AFTER: registerTool() passes schema directly to getZodSchemaObject() → works
server.registerTool(
  name,
  { description, inputSchema: enhancedSchema },
  async (params) => { /* ... */ }
);

API Changes

No external API changes. registerTool() is the non-deprecated replacement for tool() in the MCP SDK.

Output Format Changes

No output format changes.

🧪 Testing & Validation

Test Coverage Updates

• Existing Tests: All existing tests continue to pass
• New Test Cases: N/A — existing tests updated to match new call signature
• Regression Tests: Existing param-normalization tests cover the ZodEffects schema
• Edge Case Tests: N/A

Validation Scenarios

1. Backward Compatibility: All 1281 unit tests pass — tool behavior unchanged
2. New Functionality: N/A — bug fix only
3. Error Handling: Param normalization still rejects unknown properties (verified via codeql_resolve_queries test fix)
4. Performance: No performance-sensitive changes

Test Results

• Unit Tests: All pass (1281/1281 tests, 58/58 files)
• Integration Tests: codeql_resolve_queries/resolve_queries fixed; codeql_pack_install/install_pack passes in CI (fails in sandbox only due to SSL cert issue reaching GHCR)
• Manual Testing: Verified server starts and registers all tools
• Performance Testing: No regressions detected

📋 Implementation Details

Files Modified

• Core Implementation: server/src/lib/cli-tool-registry.ts — server.tool() → server.registerTool()
• Tests: server/test/src/lib/cli-tool-registry.test.ts — mock registerTool instead of tool, fix handler extraction index [0][3] → [0][2]
• Tests: server/test/src/tools/codeql-tools.test.ts — mock both tool and registerTool, split tool count assertion, fix CLI tool description access via config object
• Integration Test Runner: client/src/lib/integration-test-runner.js — params.path → params.directory for codeql_resolve_queries

Code Changes Summary

• Bug Fixes: Fixed server crash from ZodEffects schema rejection; fixed wrong parameter name in integration test
• Error Handling: Param normalization continues to work correctly via the ZodEffects .transform() pipeline

Dependencies

• No New Dependencies: Uses existing @modelcontextprotocol/sdk registerTool() API

🔍 Quality Improvements

Bug Fixes (if applicable)

• Issue: Server crashes at startup — tool() rejects ZodEffects schema as "unrecognized object"
• Root Cause: SDK's isZodRawShapeCompat() returns false for Zod schema instances, then the ToolAnnotations branch rejects nested objects in Zod internals
• Solution: Use registerTool() which routes inputSchema through getZodSchemaObject(), correctly handling any Zod schema type
• Prevention: registerTool() is the SDK's recommended non-deprecated API; it doesn't rely on fragile argument-position heuristics

Code Quality Enhancements

• Readability: Removed unsafe as unknown as Record<string, z.ZodTypeAny> cast
• Maintainability: Uses the SDK's recommended registerTool() API instead of deprecated tool() overloads

🔗 References

External References

• MCP SDK tool() deprecation: @modelcontextprotocol/sdk/dist/esm/server/mcp.d.ts lines 110-144

🚀 Compatibility & Migration

Backward Compatibility

• Fully Compatible: No breaking changes

API Evolution

• Maintained Contracts: Core API contracts preserved — all tools register with identical schemas and handlers

👥 Review Guidelines

For Reviewers

Please verify:

• ⚠️ SCOPE COMPLIANCE: PR contains only server implementation files
• ⚠️ NO UNRELATED FILES: No temporary, output, or unrelated files
• ⚠️ BACKWARD COMPATIBILITY: Existing functionality preserved
• Functionality: Updates work as described
• Test Coverage: All existing tests pass, updated tests match new API
• Code Quality: Maintains or improves code quality

Testing Instructions

npm run build-and-test   # From repo root — builds + runs all 1281 unit tests
npm run lint:fix          # Verify lint compliance

📊 Impact Assessment

Server Impact

• Startup Time: No significant impact on server startup
• Runtime Stability: Fixes startup crash — major stability improvement
• Resource Usage: No change
• Concurrent Usage: No change

AI Assistant Impact

• Improved Reliability: Server no longer crashes at startup