fix: pass tool annotations to McpServer.tool() before the callback

[vishalhabib99]

Fixes #266.

#210 added readOnlyHint: true / destructiveHint: false to the tools, but the live server doesn't return them. src/index.ts passed them after the callback, wrapped in { annotations }. In the locked SDK (1.11.2), McpServer.tool() only reads annotations between paramsSchema and the callback, then treats rest[0] as the callback, so the trailing argument was silently dropped.

This passes the annotations object itself, in the position the SDK expects (tool(name, description, paramsSchema, annotations, cb), an overload in the 1.11.2 type definitions). Tools without annotations are registered exactly as before.

Tested against @modelcontextprotocol/sdk@1.11.2: tools registered both ways, then listed through a real Client over InMemoryTransport:

OLD (current main):
  with_params:    annotations=undefined
  empty_params:   annotations=undefined
  no_annotations: annotations=undefined
NEW (this PR):
  with_params:    annotations={"readOnlyHint":true,"destructiveHint":false}
  empty_params:   annotations={"readOnlyHint":true,"destructiveHint":false}   <- empty {} paramsSchema still parsed as params
  no_annotations: annotations=undefined
callTool succeeds in both

I didn't run the Worker end to end (wrangler dev), so a quick tools/list against a preview deploy would confirm it live.

Why it matters: without annotations, clients fall back to the spec defaults (readOnlyHint: false, destructiveHint: true), so cautious hosts treat every documentation fetch as potentially destructive and may ask for approval on each call.

🤖 Generated with Claude Code

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