Agent Tool Builder

Helps define agent tools using the fail-closed design pattern: a unified class that co-locates identity, schema, security properties, and execution logic, with fail-closed defaults so new tools are safe by default.

Why this pattern matters

Three things that ad-hoc tool definitions lack:

1. Fail-closed defaults — is_read_only, is_destructive, is_concurrency_safe all default to False. A tool that forgets to declare its properties is conservatively treated as write-capable.
2. Layered execution — validate_semantics → check_permissions → _call are separate methods, so validation logic doesn't bleed into permission logic or business logic.
3. Self-contained definition — schema, description, security metadata, and execution all live in one place. No separate middleware to wire up.

Workflow