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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's added value is the return shape: slug, kind, fromCardPrice (amount, package, observation date) and foreignBrands. It also discloses the empty-results/foreignBrands fallback behavior. It omits auth requirements or limits, keeping it at 4.

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?

Front-loads the core purpose in the first sentence, then usage, then return details and fallback logic in a logical order. Slightly long with several backticked field names, but each sentence carries distinct information (when-not, usage, returns, next steps), so most of it earns its place.

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 no output schema, the description appropriately documents the return fields and the fallback-to-find_us_equivalent path, plus disambiguation guidance. It is nearly complete for a search tool; the only gap is the undocumented limit/locale parameters.

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 0% with 3 parameters, so the description must compensate. It gives rich semantics for query (brand, generic, misspelled, other scripts) but never mentions the limit or locale parameters, leaving a third of the parameters undocumented in both schema and 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?

States a specific verb+resource ('Find a medicine by name... and get its slug') and clarifies the input accepts brand, generic, misspelled or non-Latin script names. It also distinguishes itself from get_drug/compare_prices by naming the slug it produces for them, so an agent can differentiate it from siblings without opening schemas.

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 it is NOT needed ('Not needed before compare_prices, compare_basket or get_transfer_steps: they take a name as typed') and when it IS ('when the person asks what FineRx has, or a name is ambiguous'). It further routes the agent to find_us_equivalent when results is empty but foreignBrands is populated, and advises asking which candidate when several match.

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