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

The annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is covered. Beyond that, the description notes the account-link requirement and that private notes, ratings and percent read are exposed, which is genuinely useful. It says nothing about result volume, ordering, or pagination for a whole-library read, so it adds only moderate value over the annotations.

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?

Content is front-loaded: the shelves and returned fields come first, then usage phrasings, then the filter behavior, then the prerequisite. The example-query sentence earns its place by aiding selection. Minor redundancy between the status sentence and the schema description.

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 zero-required-parameter read-only tool with no output schema, the description covers what data comes back (shelves, ratings, percent read, private notes), when to reach for it, and the account prerequisite. Only the handling of large libraries (ordering, limits) is unaddressed, a small gap given the tool's simplicity.

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 100% and the single status parameter already carries an enum plus a description explaining that omitting it returns the whole library. The description's 'status filters to one shelf' largely restates the schema rather than adding format or interaction detail. Baseline 3 applies where the schema does the heavy lifting.

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 resource and scope: the linked reader's shelves, enumerated as want-to-read, reading, finished and did-not-finish, plus the fields carried with them. The 'linked reader' framing implicitly separates it from catalog tools like get_book and search_books, though it never names a sibling to contrast against.

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?

Gives three concrete user-query phrasings that map to this tool ('what am I reading', 'what's on my to-read list', 'what have I finished'), which is clear use-context guidance. It also states the 'Needs a linked Siftivo account' prerequisite. It stops short of explicit exclusions or pointing to alternatives such as get_my_book for a single title.

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