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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds genuinely new behavioral context: results are ordered newest-to-oldest and each entry carries summary, dates, vehicles, and a canonical link. It does not mention pagination or rate limits, but the added ordering and payload detail go beyond the annotations.

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?

The Portuguese lead sentence is front-loaded with source, order, and payload, and the tag-filter note follows the important content. The appended English sentence is a faithful translation rather than new information, a mild redundancy, but it aids comprehension for non-pt-BR agents so it mostly earns its place.

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, and the description compensates by enumerating the returned fields (resumo, datas, veículos, link canônico). With only two optional parameters at full schema coverage and a complete annotation set, an agent has enough to call this correctly; only pagination/edge behavior is unaddressed.

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 100%, so both 'tag' and 'limit' are already documented (including the 1-20 range and default of 10). The description's restatement of the tag as 'tópico ou ativo' with examples largely duplicates the schema, so the baseline 3 applies.

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 ('Lista as histórias e notícias de cripto mais recentes do CriptoNoticias Brasil'), including the data source, language, and sort order. It is distinguishable from 'get_historia' (single item) and 'buscar' (search), though it never names those siblings, so it stops short of full differentiation.

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?

The description notes the tag filter is optional ('Filtro opcional por tag') and gives example values, which implies the use case of browsing recent news. However, it gives no guidance on when to pick this over 'buscar', 'get_historia', or 'get_tema', so the when-to-use decision is left entirely to inference.

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