Tool Distribution & Least Privilege

In multi-agent systems, each agent should have access to only the tools it needs for its specific role (principle of least privilege).

Problem: Over-Permissioned Agents

Giving an agent too many tools (e.g., 18 instead of 4-5) degrades selection reliability by increasing decision complexity. A document analysis agent with a general-purpose fetch_url tool might:

• Conduct ad-hoc web searches (the web search agent's job)
• Access unauthorized resources
• Produce inconsistent results by mixing roles

Solution: Scoped Tools

Replace general tools with purpose-specific ones:

• fetch_url -> load_document (validates URL points to document format)
• analyze_content -> extract_web_results (clearly web-specific)

Tool Scoping Strategies

1. Rename to clarify purpose: Eliminate semantic overlap in names/descriptions
2. Validate inputs: Constrain what the tool accepts
3. Scope by capability: Give each agent only its domain's tools
4. Scoped cross-role tools: Give synthesis agents a verify_fact tool for simple lookups while complex queries go through the coordinator

tool_choice Configuration

Forced selection is useful for multi-step pipelines: force extract_metadata on the first turn, then let Claude choose tools freely on subsequent turns.