Tool discovery, versioning, permissions, cost estimation.

Tool Registry — Managing Agent Tool Libraries at Scale

As agent systems grow, managing dozens of tools requires a formal registry. A tool registry is a catalogue of available tools with their schemas, documentation, access controls, versioning, and usage metrics. Dynamic tool selection (embedding-based) retrieves relevant tools from large registries rather than always sending all tools to the LLM. Tool namespacing and permissions prevent agents from accessing tools outside their scope. Cost estimation helps budget token usage from large tool schemas.

Interactive Pipeline Flow

UnderstandImplementOptimise

📋 Register — tool + schema + docs

Register each tool with: name, description, JSON schema, tags, owner, version, cost_estimate_per_call, required_permissions.

Architecture Diagrams

Complete tool registration schema.

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Key Design Decisions

🔍Dynamic tool selection beats static tool lists

Sending all 50 tools to the LLM on every call confuses selection and wastes tokens. Embedding-based discovery returning 5-8 relevant tools improves tool choice accuracy and reduces cost by 60%.

🔐Tool permissions are a safety boundary

Agents should only see tools they're authorised to use. A customer-facing agent should never see deploy_to_production or delete_database. Enforce scopes at the registry level, not in prompts.

📊Track tool usage for cost and reliability

Tool registries that track calls, latency, and errors give you observability into agent behaviour. High error rates on a tool indicate a prompt or API issue. High latency tools may need caching.

Discussion