empty-object

Category: Semantic — schema semantics trigger this rule

Error Codes

Profile	Code	Severity
openai.so.2026-04-30	OAI-S-empty-object	Warn
anthropic.so.2026-04-30	ANT-S-empty-object	Warn

Description

Object schema with additionalProperties: false but no properties

Provider Evidence

Profile	Status	Source	Basis
anthropic.so.2026-04-30	sdk_transform	Anthropic SDK transformation	Official SDK transformation operates on declared object properties.
openai.so.2026-04-30	live_verified	OpenAI object restrictions	Observed rejection of an object schema without properties.

Rationale

Some providers may reject or misbehave when a schema permits no properties while also forbidding all extras via additionalProperties: false. This pattern is semantically valid but rarely intentional.

Bad Example

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

Good Example

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