validate

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate read-only, idempotent, non-destructive, and not open-world. The description adds significant context: clarifies structural check only, not existence; details return structure per type, including normalization and expected vs actual check digit.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is somewhat long but every sentence serves a purpose. It is well-structured with clear separation of mode explanation and return details. Could be slightly more concise but not wasteful.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the complexity (three identifier types, two modes, detailed return values), the description is fully complete. Output schema exists, and the return fields are described. No gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, but the description adds deeper semantics: explains the two modes (text vs value+type), and for each type describes the returned details (e.g., owner prefix, airline prefix). This goes beyond the schema descriptions.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool validates and parses freight identifiers (container, AWB, IMO) using check-digit algorithms, with two modes. It distinguishes from sibling tools container_lookup and airline_lookup, which serve different purposes.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly states when to use (confirm well-formedness, extract identifiers) and what it does not do (not a registry lookup). Mentions alternatives like container_lookup and airline_lookup.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.