Bug

In extensions/voice-call/openclaw.plugin.json, the OpenAI TTS provider schema (lines 518-531) has additionalProperties: false but only declares apiKey, model, and voice:

"openai": {
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "apiKey": { "type": "string" },
    "model": { "type": "string" },
    "voice": { "type": "string" }
  }
}

However, the TypeScript config interface OpenAITTSConfig in stt-openai-realtime.ts and the provider code at tts-openai.ts:85-86 accept two additional properties:

• speed (number, 0.25 to 4.0) — speech speed multiplier
• instructions (string) — speech style instructions for gpt-4o-mini-tts

With additionalProperties: false, users who configure speed or instructions in their config file would get a JSON schema validation error.

Expected behavior

Add the missing properties to the plugin schema:

"speed": { "type": "number", "minimum": 0.25, "maximum": 4.0 },
"instructions": { "type": "string" }

Impact

Medium — users cannot configure TTS speech speed or style instructions via the config file without hitting validation errors.