Package org.springaicommunity.mcp.annotation

Annotation Interface McpToolListChanged

@Target({METHOD,ANNOTATION_TYPE})
@Retention(RUNTIME)
@Documented
public @interface McpToolListChanged

Annotation for methods that handle tool list change notifications from MCP servers. This annotation is applicable only for MCP clients.

Methods annotated with this annotation are used to listen for notifications when the list of available tools changes on an MCP server. According to the MCP specification, servers that declare the listChanged capability will send notifications when their tool list is modified.

The annotated method must have a void return type for synchronous consumers, or can return Mono<Void> for asynchronous consumers. The method should accept a single parameter of type List<McpSchema.Tool> that represents the updated list of tools after the change notification.

Example usage:

 @McpToolListChanged(clients = "test-client")
 public void onToolListChanged(List<McpSchema.Tool> updatedTools) {
     // Handle tool list change notification with the updated tools
     logger.info("Tool list updated, now contains {} tools", updatedTools.size());
     // Process the updated tool list
 }

 &#64;McpToolListChanged(clients = "test-client")
 public Mono<Void> onToolListChangedAsync(List<McpSchema.Tool> updatedTools) {
     // Handle tool list change notification asynchronously
     return processUpdatedTools(updatedTools);
 }
 

Author:

Christian Tzolov

See Also:

• MCP Tool List Changed Notification

Required Element Summary

Required Elements

Modifier and Type	Required Element	Description
String[]	clients	Used as connection or client identifier to select the MCP clients that the tool change listener is associated with.

Element Details

clients

String[] clients

Used as connection or client identifier to select the MCP clients that the tool change listener is associated with.

Returns:

the client identifiers, or empty array to listen to all clients