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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful context that the data is scoped to the signed-in reader and includes shelf statuses and ratings, but it does not disclose return shape, pagination, or authentication implications beyond the word 'signed-in.'

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, well-structured sentence that front-loads the core identity ('signed-in reader's own Siftivo library') and then efficiently enumerates included content. No wasted words or redundant restatement of the tool name.

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 read-only tool with one optional parameter and no output schema, the description conveys the essential scope and contents well enough for selection. It could be slightly more explicit about what is returned (e.g., a list of books per shelf), but the provided categories make the expected output reasonably clear.

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 100%: the only parameter, status, has a clear enum and description ('Filter to one shelf. Omit for the whole library.'). The tool description mirrors the enum values but adds no new semantic detail beyond the schema, so the baseline of 3 is appropriate.

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 identifies the resource as the signed-in reader's own Siftivo library, and specifies the content categories: want to read, reading, finished, and set down, plus ratings. This distinguishes it from siblings like get_book, search_books, and add_to_library without needing to open schemas.

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 implies usage for accessing the current user's personal library, which separates it from broader search or book-level tools. However, it does not explicitly state when to prefer this over get_my_book or how it relates to add_to_library/remove_from_library, leaving some routing to inference.

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