{"version":"2.1.318","anchor":"deferred-tool-schema-hint-split-into-a-reusable-check-with","canonical_anchor":"deferred-tool-schema-hint-split-into-a-reusable-check-with","heading":"Tool errors explain when Claude called a tool before loading its details","tier":"notice","area":"Tool Search","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.318\/e\/deferred-tool-schema-hint-split-into-a-reusable-check-with","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.318","markdown":"### Tool errors explain when Claude called a tool before loading its details\n\nWhen Claude calls a deferred tool without its input format loaded, the error now shows the format or explains how to load it\n\n**What**\n\nSome tools are deferred, meaning their full description is left out of Claude's prompt until they are needed. A tool's input schema is the description of what inputs it accepts. If Claude calls a deferred tool whose schema was not in the prompt, the error now adds \"This tool's input schema was not in your prompt when you called it.\" It then does one of two things:\n\n- shows the schema\n\n- tells Claude to load the tool through the tool-search tool using `select:<name>`\n\nThe hint is left out if an earlier result already ended with the same instruction.\n\n**Why**\n\nThis should mean fewer repeated failed calls to deferred tools.\n\n- Area: Tool Search\n- Tier: You'll notice\n- Useful: 1\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}