Metric issue output missing alert rule details (query, aggregate, condition)

[Dhrumil-Sentry]

Metric issue tool output omits alert rule details (query, aggregate, condition, evaluated value), leaving the agent without the context it needs to help root-cause an alert.

The Sentry UI surfaces this clearly (see example: dataset, aggregate count(), query process_shard OR OutboxFlushError, interval, threshold, evaluated value), but none of it is included in the MCP tool response for metric_issue type issues.

• Issue type: metric_issue / category: metric
• Missing fields: alert rule query, dataset, aggregate function, interval, threshold condition, evaluated value
• Impact: agent responses are effectively useless for metric alerts — no query context means no ability to investigate signal vs. noise, trend, or root cause
• The event output currently includes only generic tags (level, interface_type) and trace info, with no alert rule payload

[linear-code]

MCP-982