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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds the useful scoping fact that results are limited to private books of the connected account, but says nothing about pagination, ordering, or empty-result behavior.

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 contributes to identifying the resource and its scope.

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 read-only list tool with full annotation coverage and no output schema, the essentials are largely there, but the undocumented limit/pagination parameter leaves a real gap an agent would want filled.

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?

There is one parameter ('limit') with 0% schema description coverage, yet the description never mentions it, its constraints (1-50 max), or any default. The low coverage means the description should have compensated and does not.

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 (List) and resource (private storybooks) with ownership scope narrowed to the connected account. It doesn't explicitly differentiate itself from siblings like picturebooks_get_book, but the verb+scope makes its role readable.

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?

Usage is only implied: the 'private storybooks owned by your connected account' phrasing hints this is a bulk enumeration of the caller's own books, but there is no explicit when-to-use, when-not, or pointer to siblings like picturebooks_get_book for single-item retrieval.

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