[BUG] Google Sheets Integration - Read Operations Returning structuredContent Validation Errors

## 📋 Issue Description The Google Sheets MCP integration has partial functionality issues. While **write operations (CREATE, UPDATE)** work perfectly, all **read operations** are failing with MCP schema validation errors. ## 🔴 Affected Tools (Read Operations) The following tools are returning `invalid_type: structuredContent null` validation errors: - [ ] `GET_SPREADSHEET_VALUES` - Error: structuredContent null - [ ] `QUERY_SPREADSHEET_DATA` - Error: structuredContent null - [ ] `GET_SHEET_HEADERS` - Error: structuredContent null - [ ] `GET_SPREADSHEET_METADATA` - Error: structuredContent null - [ ] `GET_EMPTY_COLUMN` - Error: structuredContent null - [ ] `GET_BATCH_SPREADSHEET_VALUES` - Error: structuredContent null - [ ] `ADD_FORMULA` - Error: http 500 ## ✅ Working Operations (Write) These operations function correctly: - [x] `CREATE_SPREADSHEET` - Working - [x] `UPDATE_SPREADSHEET_VALUES` - Working (Insert/Update) - [x] Google Drive integration - Working (Search, Create Files) ## 📊 Test Results **Success Rate:** 63.6% (7 of 11 operations) ### Write Operations Status All write operations successfully: - Created multiple spreadsheets with various sheets - Inserted bulk data - Updated existing records - Integrated with Google Drive ### Read Operations Status All read operations fail at MCP schema validation layer with: ``` invalid_type: structuredContent null ``` ## 🔍 Root Cause Analysis This appears to be an MCP schema initialization issue related to the `structuredContent` field in response schemas. Similar patterns have been observed in other integrations (e.g., PNCP integration). ## 💡 Recommendations 1. Investigate MCP schema initialization for read-operation tools 2. Verify `structuredContent` field mapping in output schemas 3. Check tool response transformers for null value handling 4. Add schema validation tests for both write and read operations ## 🔗 Related Information - Integration: Google Sheets (i:c94f679b-2095-428c-b93c-fa06900d9872) - Supporting Integration: Google Drive (i:05a2435f-8e55-4999-8215-91103b8db4af) - Test Date: November 7, 2025 - Pattern: Same as observed in PNCP integration issues ## 📝 Notes No sensitive data included in this report. Testing was performed with generic spreadsheet data and product catalogs.