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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so description adds value by specifying the returned fields and mentioning 'active offers across retail partners', which provides behavioral context beyond what annotations convey. No contradictions.

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 a single sentence that is front-loaded with the purpose and efficiently lists the returned fields without redundancy. Every word adds value.

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 tool with 2 required parameters, high schema coverage, and an existing output schema, the description completely covers what the tool returns. It lists all key fields and mentions offers, which is sufficient for an agent to understand the output.

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%, with both work_slug and author_slug already having detailed descriptions and examples. The description's mention of 'by author + work slug' adds no new meaning, so a baseline of 3 is appropriate.

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 uses a specific verb ('get') and resource ('audiobook detail'), and clearly lists the returned fields (title, description, cover, runtime, ISBN, genres, narrator, publisher, offers). It distinguishes from sibling tools like search_audiobooks and compare_all_offers by focusing on retrieving full detail for a specific audiobook via slugs.

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 implies usage when you have the author and work slugs, but does not explicitly state when to use this tool over alternatives like search_audiobooks or when not to use it. No exclusions or comparisons to siblings are provided.

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