popular_books

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

Annotations already establish safe read-only, idempotent behavior; the description adds the ranking metric (member-add counts), the page equivalent, the 50-item cap, and the return-field structure including chaining hints. No contradictions with 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 well structured: a lead sentence stating purpose, a concise explanation of the ranking logic, a compact parameter list, and a brief note on return fields. Every sentence adds value and there is no filler or tautology.

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?

All three parameters are explained, the optional month behavior is clear, and the return content is summarized even though an output schema exists. An agent has enough information to call this tool correctly without consulting external documentation.

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 input schema has 0% description coverage, but the description fully compensates: it defines year as a 4-digit release year, month as an optional 1-12 value versus null for the whole year, and limit with its cap. This aligns perfectly with the schema's defaults and nullability.

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, non-generic purpose: ranking books/works by release date according to Goodreads member additions, and it names the exact page it mirrors. This clearly distinguishes it from sibling tools like search_books or get_shelf by centering on the popularity-by-date dimension.

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 gives clear context on when to use it: for a given release year, optionally narrowed to a single month, with a deterministic cap on result size. It doesn't name alternative tools or exclusions, but the conditions for calling it are unambiguous.

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