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

Beyond the annotations, the description adds substantial behavioral detail: it searches the catalog, creates only on a single exact match, avoids saving web page URLs as books, and returns candidates or clarification rather than creating on ambiguous/no results. It does not explain duplicate handling or the behavioral effect of completed and async_labeling, so some behavior remains undisclosed.

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 front-loaded with the core action and then covers matching conditions, failure behavior, and candidate follow-up. Every sentence adds useful information with no repetition or filler.

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 six-parameter mutation tool with no schema descriptions, it covers the central catalog-match workflow and important no-create outcomes well. However, it leaves completed and async_labeling undefined, and duplicate handling is unaddressed, so it is not fully complete for all invocation cases.

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 0%, so the description must carry parameter meaning. It meaningfully explains title, author, isbn, and book_id in the catalog-match and candidate-add flow, but it never mentions completed or async_labeling, leaving two parameters undocumented.

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 ('Adds a book ... to the signed-in user's Linko library') and clarifies the catalog-identity approach. It also distinguishes this from saving a discovered web page URL, which helps separate it from sibling tools like add_resource.

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 clearly explains when the tool creates a Book resource (exactly one catalog match) and when it creates nothing (multiple or no matches, returning candidates or a clarification request). It also explains how to add a candidate via title and book_id. It stops short of explicitly naming the alternative tool for web-page resources, leaving that as an implication.

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