{"version":"2.1.287","anchor":"json-schema-normalizer-adds-additionalpropertiestrue","canonical_anchor":"json-schema-normalizer-adds-additionalpropertiestrue","heading":"Tool input schemas now explicitly allow extra fields","tier":"internal","area":"Tools","url":"https:\/\/changelogs.core-directive.com\/v\/2.1.287\/e\/json-schema-normalizer-adds-additionalpropertiestrue","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.287","markdown":"### Tool input schemas now explicitly allow extra fields\n\nWhen an object schema says nothing about extra fields, Claude Code now marks it as allowing them\n\n**Unclear.** Which tools' schemas go through this step is not known.\n\n**What**\n\nA schema is a description of what shape some data should have, such as which fields a tool's input takes. Claude Code tidies schemas up before using them. When an object in a schema does not say whether extra, unlisted fields are allowed, Claude Code now adds `additionalProperties` set to true, which explicitly allows them.\n\n**Why**\n\nTool descriptions sent to the model may now say plainly that extra fields are allowed, instead of leaving it unstated.\n\n- Area: Tools\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 1\/5"}