Identify a drug

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

Beyond the annotations (readOnlyHint, openWorldHint, idempotentHint), the description adds a critical behavioral constraint: 'Never guesses between look-alike names,' and specifies that it returns 'the best manufacturer labels (not repackagers).' These details clarify output selection and ambiguity handling, adding value beyond structured fields.

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 two sentences with no wasted words. The first sentence packs the core action and outputs; the second adds a key behavioral caveat. It is front-loaded with the main purpose and stays tight.

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 a single parameter, an output schema (present), and annotations covering safety and idempotency, the description supplies everything an agent needs: what input types are accepted, the resolution source, the selection rule, and the ambiguity behavior. Return format is covered by the output schema, so no additional explanation is required.

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 schema describes the parameter as 'Drug name or NDC', but the description expands it to 'brand or generic name, misspelling or NDC', clarifying that misspellings and both name types are accepted. This adds meaning beyond the schema's minimal description.

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 states a specific verb ('Resolves') and a precise resource ('a brand or generic name, misspelling or NDC through RxNorm'), and enumerates the outputs (ingredients, brands, FDA classes, manufacturer labels). It clearly differentiates from siblings like search_label and recalls_shortages by focusing on drug identification and resolution.

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 implies when to use the tool — whenever a drug name or NDC needs resolving — but it does not explicitly contrast it with siblings or state when not to use it. There are no direct alternatives mentioned, so usage is inferred rather than prescribed.

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