download_book

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

No annotations are provided, so the description carries the full burden. It only says 'Download', which implies a side-effect operation, but does not disclose where the book is saved, whether library_dir_path is required for that, what happens on failure, or any other behavioral details. This is a significant transparency gap for an action that likely writes files.

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, direct sentence that front-loads the verb and object and contains no filler. Every word earns its place by clarifying the source of the id.

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 two-parameter tool, the essential workflow is conveyed: use an id from search_books. However, the optional library_dir_path parameter is left unexplained, and with no annotations there is no guidance on side effects or postconditions. The presence of an output schema reduces the need to document return values, but the behavioral gap keeps this from being fully complete.

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 description adds meaning to 'id' by stating it comes from a search_books result, which helps an agent understand its origin and type. However, library_dir_path is entirely undocumented—neither the schema nor the description explains what it controls (presumably the save directory). With 0% schema description coverage, the description needed to compensate and only partially did.

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 ('Download'), a resource ('a book selected by its id'), and the source of that id ('from a previous search_books result'). This clearly distinguishes download_book from its sibling search_books: one searches, the other downloads.

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 phrase 'from a previous search_books result' explicitly positions this tool as the follow-up step after a search, giving clear context for when to use it. It does not provide explicit exclusions, but the intended sequence is evident enough to guide an agent correctly.

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