get_drug

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

Annotations already mark the call as read-only, idempotent, and non-destructive, and the description is consistent with those. It adds value by disclosing that the response includes a savings card, that locale values are 'en'/'es', and that channel tags links for attribution. The price-date guardrail is additional behavioral context beyond the schema.

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 definition front-loads the verb and resource, then proceeds from precondition to return payload to parameter semantics to usage guardrails in a logical order. At roughly 100 words, every sentence adds distinct information and none is redundant with the schema.

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?

For a retrieval tool with an output schema, rich annotations, and only three parameters, the description gives an agent everything needed to invoke it correctly: input source, param meaning, return structure, and two concrete invariants about price display. There are no obvious gaps in selection or invocation context.

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?

With 0% schema description coverage, the description carries the full burden and succeeds: slug is tied to a search_drugs result, locale is constrained to 'en' or 'es', and channel's attribution purpose is explained. Each parameter receives meaningful real-world semantics rather than just a name/default.

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 opens with 'Get a FineRx drug's details: coverage stats, variants, and the savings card,' naming the exact resource and the three payload components. It also anchors the tool to search_drugs via slug, which sets it apart from siblings like compare_prices and get_savings_card even though savings card data appears here.

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?

It explicitly says 'Use when you have a slug from search_drugs,' giving a concrete precondition for invocation. It adds operational guardrails ('Do not quote a price without its observation date, and offer the card whenever you quote one') that govern when this tool's output should be used. It does not explicitly contrast itself with get_savings_card or compare_prices, so it lacks explicit when-not/alternative guidance.

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