additional-properties-false

Category: Structural — overall schema structure triggers this rule

Error Codes

Profile	Code
openai.so.2026-04-30	OAI-S-additional-properties-false
anthropic.so.2026-04-30	ANT-S-additional-properties-false

Description

Every object schema must declare additionalProperties: false

Rationale

Providers require object nodes to explicitly reject extra properties.

Bad Example

{ "type": "object", "properties": { "name": { "type": "string" } } }

Good Example

{ "type": "object", "additionalProperties": false, "properties": { "name": { "type": "string" } } }