Improve AgentBuilder: Avoid modifying original config dict

[Lingbo-Huang]

Problem Description

Currently, the AgentBuilder._build() method uses pop() operations which modify the original config dict, potentially causing:

1. Side effects: If the caller retains a reference to the config, they'll find it unexpectedly modified
2. Reusability issues: The same config object cannot be used multiple times
3. Code clarity: The intent of pop() is not clear

Current Code

# veadk/agent_builder.py, line 46-63
if agent_config.get("sub_agents", None):
    for sub_agent_config in agent_config["sub_agents"]:
        agent = self._build(sub_agent_config)
        sub_agents.append(agent)
    agent_config.pop("sub_agents")  # ⚠️ Modifies original config

tools = []
if agent_config.get("tools", []):
    for tool in agent_config["tools"]:
        # ... tool processing
        tools.append(func)
    agent_config.pop("tools")  # ⚠️ Modifies original config

agent = agent_cls(**agent_config, sub_agents=sub_agents, tools=tools)

[Lingbo-Huang]

/assign

[Lingbo-Huang]

Proposed Solution

Use dictionary comprehension to create a new dict instead of modifying the original:

# Filter out special fields that will be passed explicitly
# to avoid modifying the original config and parameter conflicts
config_for_init = {
    k: v for k, v in agent_config.items()
    if k not in ["sub_agents", "tools"]
}

agent = agent_cls(**config_for_init, sub_agents=sub_agents, tools=tools)

Benefits

• No side effects
• Config reusability
• Clear intent
• Follows immutability principle