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

Goes well beyond the readOnly/idempotent annotations: it explains the ranking model (phrase, then every word, then some), the paper-round-robin tie-breaking that prevents one long-running paper from dominating, the per-title date ranges, known collection gaps, OCR misreading risk, and the dLOC front-pages-only limit. It also warns that a page is a lead rather than evidence and that hit counts are pages, not articles.

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?

Front-loaded correctly: purpose and return shape in sentence one, retrieval guidance next, archive scope and caveats after. It is long — the title/date-range inventory and the dLOC front-page note push it toward reference material — but nearly every sentence carries decision-relevant information.

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 single-parameter search with no output schema, the description fully supplies what the schema cannot: what a result contains, how ordering works, what the corpus covers and omits, and reliability limits on the returned text. An agent could invoke and interpret this tool without any other context.

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% and the schema already explains that quoting requires an intact phrase, so the description adds only the parallel framing of 'keyword or phrase' and ties it to the ranking order. Useful reinforcement, but no syntax or semantics beyond what the input schema documents.

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?

Opens with a specific verb and resource ('Find pages of U.S. Virgin Islands newspapers by keyword or phrase') and immediately states the return shape: up to 10 pages with id, citation title and URL. That is enough to distinguish it from search_newspapers, get_page and list_papers without opening a schema.

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?

Explicitly frames the tool as the 'quick lookup' entry point and routes elsewhere by name: search_newspapers for paper/date filters, match reasons and paging, list_papers for coverage gaps, and the separate document connector for laws, audits, court records and reports. Both when-to-use and when-not-to-use are stated.

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