{"version":"2.1.300","anchor":"tool-schema-refusal-tracking-added-to-request-state","canonical_anchor":"tool-schema-refusal-tracking-added-to-request-state","heading":"Sessions keep a record of tool descriptions the API refused","tier":"internal","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.300\/e\/tool-schema-refusal-tracking-added-to-request-state","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.300","markdown":"### Sessions keep a record of tool descriptions the API refused\n\nEach session now has a place to remember tool schemas that the API refused\n\n**What**\n\nA tool schema is the description of a tool and its inputs that Claude Code sends to the model. Each session's request state now includes a record of tool schemas the API refused.\n\n**Why**\n\nThis points to new handling for cases where the API rejects a tool's description.\n\n- Area: MCP\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}