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

Annotations already establish readOnly, idempotent, openWorld, and non-destructive behavior, so the safety profile is covered. The description adds real value by enumerating what is returned (title, authors, subjects, languages, copyright, download count, full-text index status), which matters since there is no output schema.

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?

A single front-loaded sentence with an enumerated parenthetical; every clause earns its place and nothing is repeated or padded.

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 read-only single-record lookup with annotations covering safety and a description enumerating the return fields, an agent has what it needs despite the absence of an output schema. Only the lack of sibling routing keeps it from the top band.

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 100% and the schema already names and exemplifies the id ('84 (Frankenstein)'). The description's 'Project Gutenberg id' adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 ('Get full catalog metadata') and resource ('a single book by its Project Gutenberg id'), and enumerates the returned fields, which implicitly separates it from the search and full-text siblings. It does not explicitly name a sibling it is not, so it falls just short of the top band.

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 phrase 'single book by its Project Gutenberg id' conveys the usage context (a known-id metadata lookup) but offers no explicit when-to-use/no-use guidance and never points to book_search or book_get_text as alternatives. Minimum viable context only.

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