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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds that the record is 'normalized' and enumerates the exact components returned, which sets expectations beyond the annotation layer. It omits any note on failure modes (invalid id, rate limits), keeping it short of a 5.

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?

Two sentences, zero filler: the first states what is fetched and what comes back, the second handles disambiguation. Front-loaded and tight.

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 single-id lookup with both annotations and an output schema present, the description covers purpose, scope, and sibling routing. Nothing an agent needs to invoke it correctly is missing.

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?

Only one parameter and schema description coverage is 100%, with the schema itself supplying the example id (2767052). The description adds nothing beyond 'by `id`', so the baseline 3 is the right ceiling — the schema carries the weight.

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 ('Fetch') and resource ('normalized Goodreads book record') keyed by `id`, then enumerates the payload (description, authors, series, genres, format, ISBNs, publication data, rating distribution). This is far more specific than the bare name and lets an agent distinguish it from goodreads_search or goodreads_book_reviews.

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 routes the agent: use goodreads_search to find books, goodreads_book_editions for editions, goodreads_book_reviews for reviews. The when-to-use-this vs alternatives distinction is stated rather than implied.

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