popular_books

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

Annotations already declare readOnly/idempotent/openWorld, so the safety profile is covered. The description adds genuinely useful behavior beyond that: a year/month with no chart raises an error rather than returning empty, and the limit is capped at 50. It does not mention pagination beyond the cap, which is the only gap.

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-loaded with purpose, then parameters, then return shape. Slightly redundant in restating the source page URL, and the trailing return-value sentence is partly unnecessary given an output schema exists, but overall efficient.

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 3-param read tool with full annotations and an output schema, the definition covers the key edge case (error on missing chart) and the entry structure. Complete enough to invoke correctly; only the parameter defaults and any alternative-tool guidance are unaddressed.

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 description coverage is 0%, so the description must carry the load, and it largely does: year as 4-digit release year, month as optional 1-12, and limit as capped at 50. It omits the default values (20, null) present in the schema, but otherwise compensates well for the missing schema descriptions.

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 ('Most popular books by release date') and anchors it to a named Goodreads chart. It is clearly distinct from siblings like search_books or similar_books, which serve different retrieval modes.

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?

Gives clear context ('Mirrors the goodreads.com/book/popular_by_date/<year>[/<month>] page') and states that results can be chained into get_book/get_reviews. However, it never explicitly says when to prefer this over search_books or book_lists, so the alternative-routing is left to inference.

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