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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description is free to add what the annotations cannot: the fields searched and the fields returned, including both page and Markdown addresses. That return-shape disclosure is genuinely useful given no output schema. It does not discuss result ordering or relevance ranking, so not a 5.

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, with the search behavior front-loaded and the return contract immediately after. Every clause carries information the agent needs.

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?

With no output schema, the description correctly compensates by listing returned fields, and it explains the matching surface for the only required parameter. The remaining gap is minor: nothing about result ordering or how filters combine (consulta + assunto), but nothing essential to invoking the tool is missing.

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%, so a 3 is the floor, and the description earns the extra point by clarifying that consulta accepts Portuguese or English and matches across title, abstract and tags – semantics the schema's single example does not convey. It stays silent on limite and assunto behavior, which the schema handles adequately.

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+resource (buscar artigos) and sharpens it with the search scope: palavras no título, no resumo e nos marcadores, em português ou inglês. It also enumerates returned fields, so the agent knows the shape of results. It does not explicitly contrast with siblings like artigos_recentes or ler_artigo, which keeps it from a 5.

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 only implied: the agent infers this is the keyword-search path and that artigos_recentes covers chronological browsing. There is no explicit when-to-use/when-not statement and no mention that assunto values come from listar_assuntos (that pointer lives only in the schema, not the description).

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