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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered; the description usefully adds the default sort order (newest first) and the fact that filtering is optional. It does not address pagination behavior or whether any total count is returned, which are the remaining behavioral unknowns for a listing tool.

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?

Two short sentences, zero filler, with the resource and ordering front-loaded before the filtering options. Nothing is redundant with the title or annotations.

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 four-parameter read-only list tool with no output schema, the description covers the core semantics but leaves the pagination story unexplained and gives no hint about what a result entry contains or how results are paged. Adequate to call the tool, but an agent must infer the limit/offset relationship from the schema alone.

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 only 25% (just the status enum restated), so the description carries real weight here; it does clarify that query is a title/author search that is distinct from status filtering. However limit and offset — including the 25 default and 100 cap — get no mention, leaving the pagination contract to the bare schema types.

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 names a specific resource (the reader's Readlink library), its default ordering (newest first), and its two filtering axes, so it is clearly a scoped listing of owned books rather than a general catalog search. It stops short of naming siblings like search_books or list_wishlist, which would settle the distinction outright.

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 implies usage via the filtering options ('Filter by reading status or by a title/author search'), which tells the agent this is the browse-and-filter path for the library. There is no explicit statement of when to prefer it over search_books (which presumably searches the whole catalog) or list_wishlist, and no exclusions.

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