feat: add EchoServer example and update docs

[m13v]

example swift mcp server with a dummy tool to quickly test in Claude desktop

Motivation and Context

we use swift sdk and need a lowlatency mcp server to talk to claude

How Has This Been Tested?

works on my side

Breaking Changes

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

[m13v]

swift_dummy_mcp_server.mp4

[huhu415]

I used your PR and found that the official usage method is so primitive? oh my god.

[m13v]

Did I oversimplify? Haha, I was personally struggling a bit to get it running so I decided to put out a concrete example that works to help others get started

…

On Sat, Apr 12, 2025 at 8:08 AM huhu415 ***@***.***> wrote: I used your PR and found that the official usage method is so primitive? oh my god. — Reply to this email directly, view it on GitHub <#55 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AY62CDES6DNTGWTJNST4ZCD2ZET5XAVCNFSM6AAAAAB2PQA2QCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOJYHA3DOMRSGM> . You are receiving this because you authored the thread.Message ID: ***@***.***> *huhu415* left a comment (modelcontextprotocol/swift-sdk#55) <#55 (comment)> I used your PR and found that the official usage method is so primitive? oh my god. — Reply to this email directly, view it on GitHub <#55 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AY62CDES6DNTGWTJNST4ZCD2ZET5XAVCNFSM6AAAAAB2PQA2QCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOOJYHA3DOMRSGM> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[huhu415]

I think it's pretty good, but I believe when this SDK is officially released, the method for constructing JSON strings shouldn't be the way it is now. It's too inconvenient.