You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.323,
ImprovementsSection of the release
What
When a tool from a connector (an MCP server, an outside program that gives Claude Code extra tools) has an argument holding an object with an id, a mimeType and a size, Claude Code does not send a file through it. Instead it returns an error saying no file was sent and the tool was not called.
The permission prompts for MCP files and for the Artifacts tool were also reworked. There is a new outcome for a request that was denied before. Artifact creation notices are now handled for subagents, which are helper agents that Claude starts to work on part of a task.
Why
A connector call that tries to pass a file this way now stops with a message saying why, instead of going through.
