atc_classify

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

Annotations already indicate readOnly, non-destructive, idempotent, and open-world. The description adds context: retrieval source (NLM RxClass), behavior for single-ingredient vs. combination products, and that one entry per code is returned. This goes beyond what annotations provide.

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 concise, well-structured with a bullet-like list of uses, and contains no redundant or extraneous sentences. Every sentence adds value.

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?

With one parameter and an output schema (not shown but hinted), the description covers the return behavior and combination product nuance. It could mention output schema details, but the provided information is sufficient for an agent to use the tool correctly.

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?

The input schema already has 100% coverage with a description for 'drug_name' (brand or generic, e.g., metformin). The description repeats 'by name' and mentions brand/generic, adding minimal extra value beyond the schema. Baseline 3 is appropriate.

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's purpose: 'Look up the WHO ATC classification(s) for a drug by name.' It provides specific verb-resource combination, examples (e.g., metformin → A10BA02), and scope (therapeutic/pharmacological hierarchy). While sibling tools exist, the purpose is distinct and unambiguous.

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?

The description explicitly lists three use cases (find ATC code, identify hierarchy, cross-reference) and explains returns (one entry per code) and behavior for combination products. It does not mention when NOT to use or alternatives, but the guidance is clear and helpful.

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