When cursor-ide-browser is missing, agent falls back to system `open` and focuses Brave

Follow-up: sanitized logs + session IDs

Data sharing on. When cursor-ide-browser is missing from agent MCP runtime, the agent fell back to shell open → system Brave focused (not CDP into Brave). Attaching the session package so support can correlate.

Correlation for this report

  • Failure mode in agent: MCP server "cursor-ide-browser" not found
  • Concurrent catalog: empty-window writer still shows toolCount=16 + leave-the-lease churn (see 01-* attachments)
  • RequestIds from the project chat window (wb62): ea519e6d-beca-48ec-a1cc-0f2014441f94, 39c62806-5a07-4e7b-a817-a2f6b664a5c8
  • composerId: 5acf3d63-e855-475f-80d3-765ec4494774

Session / identity (data sharing on)

  • machineId: 45f9fb3f-e7a9-4793-a235-3a7bb93e4e3f
  • Cursor: 3.13.21 (55434bd8062ece6fee083b82beed2aee42d253f0) Darwin arm64
  • Log session folder: ~/Library/Application Support/Cursor/logs/20260727T152911/
  • Home/empty-window workspaceId: b23abea01bc4771017b008369920af3f
  • Project workspaceId (writers): c63b395f862a583cf684909c2973e535
  • empty-window composerId: d174e224-0460-47e0-9ea0-763af6aa41df
  • jsolly-website composerId: 5acf3d63-e855-475f-80d3-765ec4494774
  • Sample requestIds (wb62 / this chat): ea519e6d-beca-48ec-a1cc-0f2014441f94, 39c62806-5a07-4e7b-a817-a2f6b664a5c8
  • Sample requestIds (wb58 / empty-window): 01ecc7d9-bae9-4492-839d-1da5719701eb, 5f3e45fc-f834-4f42-8e83-2e74cb80e63f, a85646b1-270f-459a-9cda-acc3b8fa91e0

Attachments

00-SESSION-IDS.txt
04-KEY-EXCERPTS.txt
01b-empty-window-wb58-excerpts.txt
01-empty-window-wb58-McpFileSystemWriter-b23abe.log
cursor-browser-bugs-logs-sanitized.zip

Parent catalog bug: 166850. Off-still-shows-tabs: 166854. Cross-workspace: 166856.