#7530: feat(agents): add description field for dynamic agent discovery

## Summary Adds an optional `description` field to agent config schema that enables dynamic agent discovery in multi-agent orchestration setups. ## Changes - Add `description?: string` to `AgentConfig` type - Add `description` to `AgentEntrySchema` (zod validation) - Include description in `agents_list` tool output - Add tests for description inclusion/omission ## Use Case This allows orchestrator agents to understand what each sub-agent specializes in at runtime via `agents_list()`, enabling intelligent dynamic routing without hardcoded catalogs. Example config: ```json { "agents": [ { "id": "trading", "name": "Trading Sister", "description": "Polymarket trading, market analysis, edge detection, bet execution", "workspace": "..." } ] } ``` Example `agents_list` output: ```json { "requester": "main", "allowAny": true, "agents": [ { "id": "main", "name": "Main Agent", "description": "Orchestrates all sub-agents", "configured": true }, { "id": "trading", "name": "Trading Sister", "description": "Polymarket trading, market analysis", "configured": true } ] } ``` Closes #7490 <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> Adds an optional `description` field to the agent runtime config/types and threads it through the `agents_list` tool so orchestrators can discover agent capabilities at runtime. The tool now surfaces `name` + `description` for configured agents, and tests were expanded to cover inclusion and omission cases. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with minimal risk. - Changes are additive (optional config field), localized to the agents_list tool, and covered by targeted tests; no behavior changes for existing configs beyond adding an extra optional output field. - No files require special attention <!-- greptile_other_comments_section --> <!-- /greptile_comment -->