{"version":"2.1.307","anchor":"sdk-mcp-first-query-wait-reworked-plus-a-relist-wait","canonical_anchor":"sdk-mcp-first-query-wait-reworked-plus-a-relist-wait","heading":"SDK sessions wait more carefully for MCP tools before a turn","tier":"notice","area":"Agents","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.307\/e\/sdk-mcp-first-query-wait-reworked-plus-a-relist-wait","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.307","markdown":"### SDK sessions wait more carefully for MCP tools before a turn\n\nSDK sessions now wait for each MCP server separately before the first query, and wait briefly for a pending tool list refresh before later ones\n\n**What**\n\nThe SDK lets a program run Claude Code from its own code, and can supply MCP servers, which are add-ons that give Claude extra tools. Two waits before a query have changed:\n\n- Before the first query, Claude Code now tracks each SDK MCP server on its own instead of going by a set of server names.\n\n- Before a query, Claude Code now waits, for a limited time, for a pending refresh of a server's tool list to finish.\n\nBoth waits write a note to the log if they run out of time.\n\n**Why**\n\nA turn is less likely to start while some of the SDK's MCP tools are still missing.\n\n- Area: Agents\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}