[dajiaohuang]

Summary

• Keep SDK-injected session_id, agent_id, and context properties optional in published tool schemas so host-initiated MCP App calls can omit SDK-specific fields.
• Preserve customer-defined required fields and get_more_tools' bespoke required context; update migration docs and schema tests.
• Addresses Potential issue with MCP-extensions #77. No change for sendEvent retries on any error with no stable event identity — duplicate events on an ambiguous failure #65: its follow-up confirms retry requests reuse the event's stable id.

Verification

• pnpm run lint, pnpm run typecheck, and pnpm run build passed.
• v1 tests: 806 passed, 2 skipped. The ESM consumer smoke test could not spawn pnpm on Windows (spawnSync pnpm ENOENT); all other v1 tests passed.
• v2 tests: 105 passed.
• Targeted local HTTP strict-schema checks: 5 passed. Full HTTP matrix attempted; 25 cases failed with local connection resets/bad port, so the full matrix is not green.
• No CI queried or awaited. HTTP tests use only ephemeral localhost servers; no analytics/provider or real MCP service was contacted.