atc_members

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

Beyond the annotations (readOnlyHint, idempotentHint, openWorldHint), the description adds that each member includes the substance-level ATC code via source_atc_code for disambiguation, and notes the US-centric nature of RxNorm. This provides useful behavioral context without contradicting annotations.

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 with three focused paragraphs: purpose, use cases, and additional details. Every sentence adds value, with no redundancy. It is front-loaded with the core purpose.

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 tool's moderate complexity (ATC hierarchy), the presence of an output schema, and rich annotations, the description is complete. It covers purpose, usage, parameter behavior, and a caveat about US-centricity, leaving no significant 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?

The single parameter atc_code is fully covered by the schema, but the description adds critical semantics: it explains how behavior varies by ATC level (level 1-4 returns all members, level 5 returns single substance), which is not in the schema regex description. This significantly enhances understanding.

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 specific action ('List the drugs (substances) that belong to an ATC class') and resource (ATC class members). It distinguishes itself from siblings like atc_classify and atc_lookup by focusing on enumerating members of a therapeutic class.

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 provides explicit use cases (enumerate members, build lists, explore subtree). It also gives context about RxNorm's US-centric nature and the international scope of ATC codes. However, it lacks explicit 'when not to use' or alternative tools.

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