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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real behavioral context beyond that: the timezone is fixed to Brasília, hour buckets are 0–23, orders are included only when they carry a timestamp, and click data is present only when the click report supplies an hour — a meaningful data-availability caveat.

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 dense sentence with zero filler, and the core definition (hour-of-day distribution) is front-loaded ahead of the caveats and the use case. The nested parentheticals make it slightly harder to scan but nothing is redundant.

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 does the necessary work of naming what each hour bucket contains (orders, items, commission, clicks) and flagging the conditional nature of click data. Combined with full schema coverage of the period parameters and complete annotations, an agent has what it needs to call this 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 description coverage is 100% and all three parameters (days, start_date, end_date) are documented in the schema, so the baseline of 3 applies. The description says nothing about the period window or the days-vs-start/end alternative, adding no meaning beyond the schema.

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 resource and dimension ('Distribuição por HORA do dia, 0–23, fuso de Brasília') plus the exact metrics returned: pedidos, itens, comissão, and cliques. This clearly distinguishes it from the other breakdown siblings (category, channel, subid, status, advertiser), which slice by different dimensions.

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?

'Use para recomendar horários de postagem' gives an explicit decision context for selecting this tool. It stops short of naming alternatives or exclusions (e.g., when to prefer painel_get_trends or painel_compare_periods instead), so it falls just below the full when/when-not bar.

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