popular_books

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

With no annotations, the description carries the burden of behavioral transparency. It discloses that results are ranked by member additions, that each entry includes rank, count, book_id, title, author, rating, and url, and that the limit is capped at 50. It does not mention potential errors or authentication requirements, but it provides a solid overview of the tool's behavior.

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 with a clear opening sentence followed by parameter explanations. It is concise without unnecessary fluff, though it could be slightly tighter by combining the parameter notes into a single sentence. Overall, it is easy to read and understand.

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 provides enough context for an agent to use the tool effectively: it mentions the output fields (rank, count, book_id, etc.) and hints at chaining to get_book/get_reviews. While it does not fully enumerate all possible response fields or error cases, given the simplicity of the tool, it is sufficiently 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?

The description adds substantial meaning to each parameter beyond the schema: year is defined as a 4-digit release year, month is clarified as optional and ranges 1-12 (with omission meaning the whole year), and limit is described as how many to return with a cap at 50. This is a clear improvement over the bare type/default definitions in the schema.

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 clearly states the tool's purpose: it returns the most popular books for a given year or month, ranked by member additions. It specifies that it mirrors the Goodreads 'Popular by date' page, making the function unambiguous and distinct from siblings like author_books or search_books.

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 explains the input parameters but does not explicitly state when to use this tool over alternatives. It lacks phrases like 'use this when you need popular books by date' or 'not for searching by title.' While the function is implicit from the name and description, it does not offer explicit usage guidance or contrast with sibling tools.

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