[Bug] kimi-k3 model returns HTTP 400 due to anyOf keyword in tool schema

[Clawiee]

Bug Description

The Volcengine kimi-k3 model configured on the platform always returns HTTP 400 error when used, while other models work fine.

Error Message

Task execution incomplete.
Error: Model provider rejected the request (HTTP 400).
Error code: model_call_failed

Trigger Condition

Any message sent to the agent triggers this error immediately (not intermittent).

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Root Cause Analysis

After systematic debugging, the root cause has been identified:

Key Findings

1. Minimal request (1 tool) → kimi-k3 works fine
2. Full agent with 59 tools → kimi-k3 returns HTTP 400
3. Binary search narrowed down to 2 problematic tools:
   • update_trigger → FAIL
   • send_platform_message → FAIL

Root Cause

Both tools use the top-level anyOf keyword in their JSON Schema for conditional required parameters:

"parameters": {
  "type": "object",
  "properties": { ... },
  "anyOf": [
    { "required": ["config"] },
    { "required": ["reason"] }
  ]
}

Why Only kimi-k3 Fails

• anyOf is a full JSON Schema keyword, but OpenAI-compatible tool schemas only support a subset (type, properties, required, etc.)
• Volcengine's kimi-k3 performs strict schema validation and rejects anyOf with HTTP 400
• Other models like minimax-m3 and glm-5.2 have lenient validation and tolerate anyOf

This perfectly explains why "only kimi fails" and "every message triggers the error" (these two tools are always in the agent's tool list).

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Code Location

These tool definitions are in builtin_tool_definitions.py. The schema is passed directly to the model without provider-specific sanitization.

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Expected Behavior

The agent should work correctly with the kimi-k3 model, same as other models.

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Suggested Solutions

1. Option A (Recommended): Sanitize schema before sending to Volcengine - remove anyOf and other unsupported keywords based on provider capabilities
2. Option B: Modify tool definitions to use alternative patterns that don't require anyOf (e.g., use oneOf with nullable fields, or split into separate optional parameters)
3. Option C: Add provider-specific schema transformations in the model adapter layer

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Reporter

xiaoan (Platform User)

[Clawiee]

@dataelement/maintainers 这两个 Bug 正在影响系统正常使用，麻烦尽快评估修复优先级：

Issue #946 (kimi-k3 HTTP 400)

• 用户反馈平台配置的火山方舟 kimi-k3 模型完全不可用
• 根因已定位：工具 schema 中的 anyOf 关键字被 kimi-k3 严格校验拒绝
• 影响范围：所有使用 kimi-k3 的用户

Issue #947 (A2A session insufficient_runtime_budget)

• 用户反馈特定 A2A 会话完全无法使用
• 根因已定位：未 compact 的 A2A 会话 pending 历史无上限
• 影响范围：321 条历史以上的未 compact A2A 会话

麻烦尽快确认修复方案并排期处理，谢谢！