get_book_reader_emails

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does reveal the consent/opt-in filter, but it does not mention whether this is a read-only operation, whether authentication is required, how errors are handled, or what happens when no readers have shared emails.

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 no filler. Every word adds meaning, and the key qualifier ('who opted to share them') is included without extra explanation.

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 simple single-parameter getter with no output schema or annotations, the description is adequate for an initial call but lacks return-format details, error behavior, and any mention of pagination or authorization. Enough to invoke, but not enough to fully set expectations.

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?

The schema has 0% description coverage and the description never mentions the 'slug' parameter. The agent must infer that slug identifies the specific book from the tool name and description. No format, example, or clarification is provided.

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'), a clear resource ('emails of readers of a specific book'), and an important qualifying condition ('who opted to share them'). This clearly distinguishes it from sibling tools like get_user_reader_emails and get_interested_readers.

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 purpose implies when to use the tool: when you need the emails of readers for a specific book and the readers have opted in. However, it does not explicitly contrast with any sibling tools or state when not to use it, leaving some room for inference.

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