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

Annotations declare readOnlyHint and openWorldHint, so safety is covered. The description adds genuinely useful context beyond that: it is credential-free public data served via the autocomplete endpoint and returns only book results, which tells the agent about result type and auth requirements.

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 endpoint constraints, then params, then the sibling pointer. Efficient, though the explicit restatement of both parameters is slightly redundant given the schema.

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?

With an output schema and annotations present, the description needn't explain returns or safety. It covers the endpoint constraint (book results only) and credential-free nature, leaving little an agent needs missing for a two-param search.

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 description simply restates the schema ('q: Search query', 'limit: Max results, default 10, max 50') with no added syntax, matching rules, or examples. Baseline 3 is correct when the schema already documents both params.

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 and resource ('Searches Goodreads books'), plus the searchable fields (title/author), and implicitly contrasts with goodreads_book for retrieval. An agent can distinguish this from the sibling book-detail tool without opening either schema.

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 to the alternative: 'Use goodreads_book to get a Goodreads book,' establishing a search-then-detail pattern. It doesn't state when-not-to-use or limits beyond 'book results only,' but the context is clear.

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