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

Annotations already declare destructiveHint=true, so the destructive nature is covered. However, the description adds no additional behavioral context beyond that, such as permanence, reversibility, cascading effects, or required permissions. It simply restates the obvious without enriching the agent's understanding of side effects.

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, concise sentence with no filler. It is front-loaded with the action and resource, making it easy to scan. Every word contributes meaning, exemplifying excellent conciseness.

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 delete operation with one parameter, the description is sufficient. The parameter is fully documented in the schema, destructive behavior is noted in annotations, and no output schema exists. While it omits potential details like idempotency or error behavior, these are not critical for a basic delete action. The description covers the essentials adequately.

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 input schema fully documents the single parameter book_id with a clear description ('ID of the book to delete'). The tool description adds no further parameter semantics, but since schema coverage is 100%, the baseline of 3 is appropriate. No extra value is provided by the description.

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 clearly states the verb (Delete) and the specific resource (book from the library). It is unambiguous and distinguishes from other delete_* siblings that target different resources like notes, tasks, or bookmarks. No ambiguity exists about what this tool does.

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 offers no explicit guidance on when to use this tool versus alternatives. It does not mention any conditions, exclusions, or comparisons to related tools such as update_book or create_book. For a tool with many siblings, this lack of usage context leaves the agent to infer usage solely from the name.

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