{"version":"2.1.301","anchor":"mcp-server-tool-call-handler-adds-cpuserving-accounting","canonical_anchor":"mcp-server-tool-call-handler-adds-cpuserving-accounting","heading":"Tool calls served by Claude Code as an MCP server are now tracked for CPU use","tier":"internal","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.301\/e\/mcp-server-tool-call-handler-adds-cpuserving-accounting","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.301","markdown":"### Tool calls served by Claude Code as an MCP server are now tracked for CPU use\n\nWhen Claude Code serves tools to other programs over MCP, each call is now tracked, and in one mode results carry a CPU usage report\n\n**What**\n\nClaude Code can act as an MCP server, meaning other programs can call its tools through the Model Context Protocol. Each tool call in that mode is now tracked as a served call. In one particular tool-host mode, the result also carries a report of CPU use. Before, results were returned directly.\n\nThe change is in the code that handles `CLAUDE_CODE_MCP_SERVE_SETTINGS`.\n\n**Why**\n\nThis appears to add CPU accounting for tool calls that Claude Code handles on behalf of other programs.\n\n- Area: MCP\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 3\/5\n- Scope: individual\n- Heads-up: no"}