Parameter serialization bug: Object parameters received as strings in create-pages and move-pages tools

Bug Description

Complex object parameters are being incorrectly serialized as strings in multiple Notion MCP tools, causing "Expected object, received string" validation errors.

Affected Tools

• create-pages (when using parent parameter)
• move-pages (when using new_parent parameter)

Error Message

MCP error -32602: Invalid arguments for tool create-pages: [
  {
    "code": "invalid_union", 
    "unionErrors": [{
      "issues": [{
        "code": "invalid_type",
        "expected": "object", 
        "received": "string",
        "path": ["parent"],
        "message": "Expected object, received string"
      }]
    }]
  }
]

Reproduction

create-pages example:

{
  "pages": [{"content": "test", "properties": {"title": "Test"}}],
  "parent": {"database_id": "example-database-id"}
}

move-pages example:

{
  "page_or_database_ids": ["example-page-id"],
  "new_parent": {"database_id": "example-database-id"}
}

Both fail with the same "Expected object, received string" error.

What Works

• create-pages without parent parameter ✅
• create-database with parent parameter ✅ (interestingly)
• All simple parameter operations ✅

Impact

Cannot programmatically populate databases or organize pages, requiring manual entry for all database operations.

Environment

• Claude Sonnet 4 via Claude.ai
• Date: July 15, 2025