fix(mcp): add missing required fields to document query source filters (#2729)

GetByUrlAsync omitted `search_title` and GetStructureAsync omitted both
`search_title` and `type` from the Elasticsearch _source filter. Since
DocumentationDocument marks these as `required`, the JSON deserializer
threw on every response: "missing required properties including:
'search_title'". Adding them to the source filter fixes the 2 broken
document tools.

Co-authored-by: Claude <claude@anthropic.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

Author: 3 people

src/api/Elastic.Documentation.Mcp.Remote/Gateways/DocumentGateway.cs

@@ -28,24 +28,25 @@ public class DocumentGateway(
 				.Indices(clientAccessor.Options.IndexName)
 				.Query(q => q.Term(t => t.Field(f => f.Url).Value(normalizedUrl)))
 				.Size(1)
-				.Source(sf => sf.Filter(f => f.Includes(
-					e => e.Url,
-					e => e.Title,
-					e => e.Type,
-					e => e.Description,
-					e => e.NavigationSection,
-					e => e.Body,
-					e => e.Parents,
-					e => e.Headings,
-					e => e.Links,
-					e => e.AiShortSummary,
-					e => e.AiRagOptimizedSummary,
-					e => e.AiQuestions,
-					e => e.AiUseCases,
-					e => e.LastUpdated,
-					e => e.Product,
-					e => e.RelatedProducts
-				))),
+			.Source(sf => sf.Filter(f => f.Includes(
+				e => e.Url,
+				e => e.Title,
+				e => e.SearchTitle,
+				e => e.Type,
+				e => e.Description,
+				e => e.NavigationSection,
+				e => e.Body,
+				e => e.Parents,
+				e => e.Headings,
+				e => e.Links,
+				e => e.AiShortSummary,
+				e => e.AiRagOptimizedSummary,
+				e => e.AiQuestions,
+				e => e.AiUseCases,
+				e => e.LastUpdated,
+				e => e.Product,
+				e => e.RelatedProducts
+			))),
 				ct);
 
 			if (!response.IsValidResponse || response.Documents.Count == 0)
@@ -106,17 +107,19 @@ public class DocumentGateway(
 				.Indices(clientAccessor.Options.IndexName)
 				.Query(q => q.Term(t => t.Field(f => f.Url).Value(normalizedUrl)))
 				.Size(1)
-				.Source(sf => sf.Filter(f => f.Includes(
-					e => e.Url,
-					e => e.Title,
-					e => e.Parents,
-					e => e.Headings,
-					e => e.Links,
-					e => e.Body,
-					e => e.AiShortSummary,
-					e => e.AiQuestions,
-					e => e.AiUseCases
-				))),
+			.Source(sf => sf.Filter(f => f.Includes(
+				e => e.Url,
+				e => e.Title,
+				e => e.SearchTitle,
+				e => e.Type,
+				e => e.Parents,
+				e => e.Headings,
+				e => e.Links,
+				e => e.Body,
+				e => e.AiShortSummary,
+				e => e.AiQuestions,
+				e => e.AiUseCases
+			))),
 				ct);
 
 			if (!response.IsValidResponse || response.Documents.Count == 0)