When validating structured data, you may encounter warnings about missing or invalid schema fields in Google Rich Results Tool. However, not all warnings indicate problems that require action.

In some cases, Google Rich Results Tool may flag optional schema properties. These warnings are informational recommendations rather than validation errors and do not necessarily indicate issues with your schema implementation.

Because Google Rich Results Tool and schema.org validator serve different purposes, it is possible for a page to pass schema.org validation while still displaying optional-field warnings in Google's tools.

#### **🔍 Why Do Different Validation Tools Show Different Results?**

Google Rich Results Tool and schema.org validator serve different purposes and therefore may report different results.

#### **🧩 schema.org Validator**

The schema.org validator checks your structured data against the official schema.org specification.

If your markup complies with schema.org requirements, the validator will consider it valid—even if certain optional properties are not present.

#### **🔎 Google Rich Results Tool**

Google Rich Results Tool focuses on Google's interpretation of structured data and may highlight additional fields that Google recommends but does not require. These recommendations often appear as warnings rather than errors.

As a result, it is possible for structured data to:

- Pass validation in schema.org validator
- Display warnings in Google Rich Results Tool
- Remain fully valid and functional

#### **🏷️ A Common Example**

- `mainEntityOfPage`

The presence of these kind of warnings does not automatically indicate a problem with your schema implementation.

#### **🔑 Key Facts**

- ### ✅ schema.org validator is the authoritative reference for schema.org compliance
- ✅ Optional fields are not required for valid schema implementation
- ⚠️ Google Rich Results Tool may display recommendations for optional fields
- ℹ️ Not every warning represents a technical issue that needs correction
- 📈 Optional-field warnings are not ranking factors by themselves
- ✅ Passing schema.org validation generally indicates your structured data is implemented correctly

#### **🛠️ What Should You Do?**

When validating structured data:

#### **✅ Recommended Approach**

1. Use the schema.org validator as your primary validation source:

   - <https://validator.schema.org/>
2. Review Google Rich Results Tool warnings and recommendations.
3. Prioritize fixing:

   - Missing required properties
   - Invalid values
   - Syntax errors
   - Structured data validation errors
4. Evaluate optional-field warnings individually rather than treating them as critical issues.

#### **🎯 Important Reminder**

Warnings related to optional schema properties are generally informational and should not be treated the same way as validation errors.

#### **✅ Conclusion**

OTTO and Search Atlas use schema.org as the primary source of truth for structured data validation.

Google Rich Results Tool may display warnings for optional schema properties that are not required by schema.org. This behavior is expected and does not necessarily indicate a problem with your schema implementation.

If your structured data passes schema.org validation and contains all required properties, optional-field warnings can generally be treated as recommendations rather than errors requiring action.