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

Annotations already declare read-only, idempotent, non-destructive behaviorstant. The description goes further, explaining the purpose of the slug, the kind field, fromPrice, and the foreignBrands edge case including the instruction to call find_us_equivalent rather than guessing. This reveals meaningful runtime behavior beyond 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 core purpose, returned fields, and usage guidance are front-loaded. The foreign brand fallback is a valuable addition in a separate, clearly formatted paragraph. No wasted words.

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?

The description covers the essential behavior (query resolution, slug usage, generic/brand kind, price, foreign brand fallback) well. It omits any mention of the optional limit parameter, but the schema default and title cover that. For a search-first tool the guidance is otherwise complete.

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 has no descriptions (0% coverage). The description clarifies that query is a drug name or localized alias, but says nothing about the limit parameter, its default, or how pagination/counting works. Only partial meaning is added for the required parameter.

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 a specific verb and resource ('Search FineRx for drugs by name or localized alias') and states exactly what is returned (slug, kind, fromPrice) and how to use it (with get_drug). It clearly distinguishes this tool as the name-resolution entry point vs siblings like get_drug or find_us_equivalent, so an agent can select it unambiguously.

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 says 'Use this first to resolve a drug name to a slug' and explains when to call find_us_equivalent instead when results are empty but foreignBrands is populated. This gives clear when-to-use and when-not-to-use guidance relative to the most likely alternative.

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