Expose field descriptions through the CS MCP connector's metadata

Right now, when an AI agent using the Gainsight MCP server calls the object metadata tool to inspect a field, it only gets back fieldName, label, dataType, and lookup/picklist info — not the field's Description or help text that we already fill in during field configuration.

That's a real gap for anyone building AI workflows on top of Gainsight: the agent has to rediscover a field's meaning by trial and error, even when we've already documented it in the UI. Concrete example we hit: one of our custom lookup fields actually stores an external system ID rather than a Gainsight GSID — exactly the kind of thing a one-line field description would explain, but the MCP tool has no way to surface it.

Reports already do this well — reportDescription flows through the report metadata tool when it's filled in. Extending that same pattern to field-level descriptions on objects would make MCP-based agents meaningfully more reliable, with zero extra admin effort beyond what's already being documented today.