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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds genuinely useful semantics beyond that — matching requires ALL query words, i.e. conjunctive matching — but says nothing about ranking, result shape, or how paging behaves at the cap.

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 tight sentence with no filler, and the essential matching rule is front-loaded. Minor cost: "passages in the book and collector profiles" is slightly ambiguous to parse, but nothing is wasted.

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?

There is no output schema, so the description is the only place an agent could learn what comes back — passages with highlights, ranked or unranked, truncated by limit — and it says none of that, nor how limit interacts with results. For a search tool with zero schema documentation, this leaves a real gap.

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 compensate and it partly does: it defines query as a conjunctive word match. The limit parameter (default 20, max 50) is never mentioned, leaving half the parameters undocumented anywhere.

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 verb ("Find passages") and a bounded resource scope ("the book and collector profiles"), which lets an agent distinguish it from the sibling search_works. It stops short of explicitly contrasting itself with search_works, so the differentiation is inferable rather than stated.

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?

Usage is implied by scope: use this for book passages and collector profiles, presumably search_works for works. There is no explicit when-to-use/when-not or named alternative, so the agent must infer the routing from the scope phrase alone.

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