You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
Remote ControlArea: what it touches
ImprovementsKind: in v2.1.248,
ImprovementsSection of the release
What
In bridge mode (CLAUDE_CODE_ENVIRONMENT_KIND=bridge), the per-server error map returned for an MCP server update now only passes through known reasons such as "Blocked by enterprise policy (allowedMcpServers/deniedMcpServers)", "Ignored in hermetic mode (not declared in user config)" and "Ignored in a Remote Control session: MCP servers are loaded only from the verified startup config on this machine". Anything else becomes "connection failed". Outside bridge mode the original text is still returned.
Details
Two error shapes are additionally allowed by pattern: Server status: <status> and Server not found: <name> (name limited to 64 characters of letters, digits, space, underscore, dot and hyphen).
Server-name keys are sanitized too and duplicates get a #2 suffix.
Evidence
Ignored in a Remote Control session: MCP servers are loaded only from the verified startup config on this machine
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
