Refactor: Simplify ServerCapabilities builder API for completions

Signed-off-by: Christian Tzolov <[email protected]>

Author: tzolov

Diff for: mcp-spring/mcp-spring-webflux/src/test/java/io/modelcontextprotocol/WebFluxSseIntegrationTests.java

@@ -774,7 +774,7 @@ void testCompletionShouldReturnExpectedSuggestions(String clientType) {
 		};
 
 		var mcpServer = McpServer.sync(mcpServerTransportProvider)
-			.capabilities(ServerCapabilities.builder().completions(new CompletionCapabilities()).build())
+			.capabilities(ServerCapabilities.builder().completions().build())
 			.prompts(new McpServerFeatures.SyncPromptSpecification(
 					new Prompt("code_review", "this is code review prompt", List.of()),
 					(mcpSyncServerExchange, getPromptRequest) -> null))

Diff for: mcp/src/main/java/io/modelcontextprotocol/spec/McpSchema.java

@@ -360,8 +360,8 @@ public static class Builder {
 			private ResourceCapabilities resources;
 			private ToolCapabilities tools;
 
-			public Builder completions(CompletionCapabilities completions) {
-				this.completions = completions;
+			public Builder completions() {
+				this.completions = new CompletionCapabilities();
 				return this;
 			}