feat(server): tool call support context

[taobaorun]

Motivation and Context

Current call tool flow can't get some information about the request.for example the header value

• handle with context (map)
• context has the current original request. e.g. ServerRequest
• has the current sessionId

if has the context,the tool method can get more information.

 @Tool(description = "Get the current date and time in the user's timezone")
        String getCurrentDateTime(@ToolParam(required = false) ToolContext context) {
        context.getContext().get("sessionId")
        return LocalDateTime.now().atZone(LocaleContextHolder.getTimeZone().toZoneId()).toString();
    }

public class RequestContext {

	/**
	 * the original request object
	 */
	private Object request;

	private final Map<String, Object> context;

	public RequestContext(Map<String, Object> context) {
		this.context = Collections.unmodifiableMap(context);
	}

	public Map<String, Object> getContext() {
		return context;
	}

	public Object getRequest() {
		return request;
	}

	public void setRequest(Object request) {
		this.request = request;
	}

}

How Has This Been Tested?

Worked in the real application

Breaking Changes

• SyncToolSpecification AsyncToolSpecification definition with the context

the request record wrapper the params and context

/**
 * @param params the parameters of the request.
 * @param context the request context
 */
public record McpRequest(Object params, RequestContext context) {
}

//before
new McpServerFeatures.SyncToolSpecification(tool, (exchange, params) -> {
          ...
        });

//after
 new McpServerFeatures.SyncToolSpecification(tool, (exchange, request) -> {
          ...
        });

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

[taobaorun]

@tzolov Please review this PR for this situation and see if there’s a better way to solve it? Thanks

[chenjianzeng0604]

I also have this demand. When can this demand be supported?

[taobaorun]

python sdk support context modelcontextprotocol/python-sdk#380