{"version":"2.1.295","anchor":"tool-search-now-normalizes-the-query-and-checks-non-deferrab","canonical_anchor":"tool-search-now-normalizes-the-query-and-checks-non-deferrab","heading":"MCP tool loading: faster bounded tool search, deferral rules and retrying servers","tier":"notice","area":"Tool Search","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.295\/e\/tool-search-now-normalizes-the-query-and-checks-non-deferrab","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.295","markdown":"### MCP tool loading: faster bounded tool search, deferral rules and retrying servers\n\nTool search is bounded and time-sliced, some built-ins cannot be deferred, and MCP servers that will retry are reported as unavailable only for now\n\n**What**\n\nMCP (Model Context Protocol) servers are outside programs that give Claude extra tools. Tool search is how Claude loads tools it was not given up front; tools held back this way are called deferred.\n\n- Tool search now cleans up the query first and matches `select:` with a shared pattern.\n\n- Tool search pauses regularly while scoring tools so other work can run, and cuts queries, search hints and `select:` lists to set limits.\n\n- Deferral decisions now take a `nonDeferrableBuiltins` list into account, meaning some built-in tools can no longer be held back.\n\n- An MCP tool's description now differs when the model loaded it through tool search.\n\n- When Claude waits for an MCP tool to appear, a new `connectedGraceMs` option can keep it waiting while the server is already connected. It defaults to 0.\n\n- Failed MCP servers now carry `willRetry`. The message Claude sees now splits them: servers that will retry are unavailable \"for now\", and the session retries them in the background when you send a message, so their tools may appear later. Others stay \"unavailable for this session\". Claude is told to suggest asking again in a minute for the retrying ones.\n\n**Why**\n\nLarge sets of MCP tools should be less likely to freeze Claude Code during a search, and Claude gives more accurate advice when a server is only temporarily unreachable.\n\n- Area: Tool Search\n- Tier: You'll notice\n- Useful: 3\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: no"}