## What changed
- Keep complete MCP namespace descriptions in tool-search source metadata.
- Raise the namespace tool-spec description limit from 1,000 bytes to 512 KiB,
truncating at a UTF-8 character boundary only when the new limit is exceeded.
## Testing
- Cover descriptions beyond the former limit and multibyte truncation at 512 KiB.
- Update SSE and stdio MCP tests to verify that complete server instructions are
preserved without hiding tools.
GitOrigin-RevId: 000bfcafb3df348065ae451685bfbf978a0e3248