What
Apps built on Claude Code can send an mcp_status request to ask about MCP servers, the outside programs that give Claude extra tools. A live reply that would be too large now shrinks instead of failing:
- Each server's list of tools is replaced with
toolCount, the number of tools. serverInfoandcapabilitiesare left out. When they are missing, that means unknown, not empty.- The request's description now also mentions
mcp_status_no_config_v1.
Before, the reply included each server's configuration, and an oversized reply was an error.
Why
Apps connected to many MCP servers with many tools should stop getting errors back from status checks. If you read these replies, treat a missing serverInfo or capabilities as unknown.
Names in the bundlemcp_statustoolCount
Documented inclaude-code/agent-sdk/mcp