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

With destructiveHint=true already declared, the description adds critical detail beyond the annotation: what is destroyed (shelf, progress, notes) and the notable exception (rating is preserved). It also discloses the prerequisite of a linked Siftivo account. This is exactly the extra context the annotation alone does not provide.

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?

Three compact sentences with zero waste: outcome and side effects first, then the sibling alternative, then the account prerequisite. Front-loaded and easy to scan.

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 one-parameter destructive tool with no output schema, the description covers outcome, side effects, alternative, and prerequisites. The only missing piece is guidance on the workId parameter, which keeps it from a perfect score.

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 coverage is 0% and there is only one parameter (workId), which the schema names but does not describe. The description does not explain the workId parameter (e.g., where to obtain it, format). Baseline for 0% coverage is not automatic; here the description is silent on the sole parameter, leaving a gap, though low complexity limits the impact.

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 states a specific verb and resource ('Take a book off the signed-in reader's shelves entirely') and explicitly distinguishes the tool from its sibling add_to_library by explaining the shelf-move case. An agent can select it without ambiguity.

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?

It names the alternative ('Moving a book between shelves is add_to_library with a new readingStatus') and provides example phrasings ('take X off my shelves', 'remove X from my list'). When-to-use and when-not-to-use are both covered explicitly.

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