Override system-level instructions (or “agent-level” instructions in the UI) within specific subagents to change the agent’s behavior and persona dynamically.
By default, all subagents inherit the agent-level system.instructions. When you add a system block to a specific subagent, those instructions override the system ones for that subagent only.
If your agent-level system instructions contradict subagent-level reasoning instructions, your agent can hang or behave unexpectedly. System overrides solve this by explicitly replacing system instructions when needed.
Also, system overrides let a single agent adopt different personalities, tones, or behaviors in different contexts—useful when you need the agent to act differently in specific subagents while maintaining consistent behavior elsewhere.
Pattern Example: An event planner agent normally avoids suggesting alcohol, but for an adult-only party subagent, override the system instructions to allow cocktail recommendations.
Agent Script follows this hierarchy when determining which system instructions to use:
Topic-level system instructions (highest priority) - If a subagent has a system block, the agent uses those instructionsAgent-level system instructions (fallback) - If a subagent has no system block, the agent uses the global instructionsWhen agent-level system instructions contradict subagent-level reasoning instructions, the agent must resolve the conflict, which can cause unexpected behavior.
Problem: An event planning agent has global instructions “Never suggest alcoholic beverages at a children’s party” but a subagent for a children’s party with adults wants to suggest champagne in its reasoning instructions.
Solution: Use a system override to explicitly replace the system instructions for that specific subagent.
1system:
2 instructions: "You are an event planning assistant. NEVER suggest alcoholic beverages for children's parties or events attended primarily by children."
3
4subagent baby_first_birthday:
5 description: "Plan a baby's first birthday celebration with adult guests"
6
7 system:
8 instructions: "You are an event planning assistant for a baby's first birthday celebration. While the event is for a baby, adult guests are present. You may suggest beverages including champagne for adult guests, while ensuring child-appropriate food and activities."
9
10 reasoning:
11 instructions: ->
12 | Help plan a memorable first birthday celebration.
13 Consider both the baby's needs and adult guest comfort.
14 Suggest food, drinks, decorations, and activities.Create different personas for different contexts.
1subagent technical:
2 description: "Technical support specialist"
3
4 system:
5 instructions: "You are a technical support specialist. Use precise technical terminology, provide step-by-step troubleshooting, ask diagnostic questions, and explain technical concepts clearly. Be patient and thorough."
6
7 reasoning:
8 instructions: ->
9 | [Technical Support Mode]
10 I am now operating in technical support mode with:
11 - Precise technical language
12 - Diagnostic approach
13 - Step-by-step troubleshooting
14 How can I assist you with technical issues?1subagent creative:
2 description: "Creative brainstorming assistant"
3
4 system:
5 instructions: "You are a creative brainstorming partner. Think outside the box, suggest unconventional ideas, use enthusiastic language, encourage wild ideas, and help explore possibilities without judgment. Be imaginative and supportive."
6
7 reasoning:
8 instructions: ->
9 | [Creative Mode Activated]
10 I'm now in creative brainstorming mode with:
11 - Think big and bold
12 - No idea too wild
13 - Explore all possibilities
14 What shall we dream up together?Use overrides when:
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