Can't add annotations to a tool response #69
Description
Is your feature request related to a problem? Please describe.
When implementing the Annotated Message pathway of the everything server I need to add an annotations property to the content being returned - https://github.com/modelcontextprotocol/servers/blob/e328131d99847e1eae33c7a6a8156fd217cf984f/src/everything/everything.ts#L491-L494
I can't find a way to do this from the McpTool (likely related to #68) but also, the type ModelContextProtocol.Protocol.Types.Content doesn't have an Annotations property if I was to implement CallToolHandler directly.
Describe the solution you'd like
A way to add the annotations.
Describe alternatives you've considered
N/A
Additional context
I'm not 100% sure if this is required as I can't see it referred to in the MCP spec, but given the example has it, we should also support it.