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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds the return field list (IDs, names, dates, works, subjects) but not deeper behavior like rate limits, ordering, or result richness. With annotation coverage, this is adequate but not rich.

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 sentences, no filler. Purpose and result fields in the first sentence; usage guidance in the second. Efficient and front-loaded, though the second sentence could arguably be part of usage guidelines rather than purpose, it doesn't waste words.

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?

Given an output schema exists and annotations cover safety, the description provides the key context: what fields appear in results and how to consume them with sibling tools. Pagination behaviors are in the schema. Nothing critical is missing for an agent to call it correctly.

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% for all three parameters; the description adds nothing beyond what the schema already states (e.g., 'Partial names and alternate names work' is duplicated from the query description). Baseline 3 is appropriate because 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 verb and resource: 'Search Open Library authors by name.' Clearly distinguishes itself from sibling retrieval tools by naming the follow-up tools (openlibrary_get_author, openlibrary_get_author_works) that consume its output. Immediate clarity on what it does and how it fits.

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?

Provides explicit context on how to use the returned author IDs for subsequent tool calls, which tells the agent why this tool exists. Doesn't explicitly state when not to use it vs. search_books, but the mention of alternatives creates a clear usage path. Minor gap: no exclusions or conditions.

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