wb_advert_costs

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does not explain the return shape, granularity, currency, timezone, pagination, or whether this is a read-only historical view. The word 'history' implies a read operation, but that is not enough for a tool with no structured safety metadata.

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 description is a single, front-loaded sentence with no filler. It conveys the core purpose immediately, and the Russian parenthetical adds useful context for non-English users. No words are wasted.

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 tool that takes two required date parameters and returns historical data, the description omits important operational details like output format, date semantics, and relationship to sibling advert/finance tools. With no output schema and no annotations, the description alone does not give an agent enough to invoke it confidently.

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 only 50%: date_from has a format hint but date_to does not. The description adds only the vague phrase 'for a period,' which restates the two date parameters rather than clarifying date_to format, inclusive boundaries, or maximum range. It does not compensate for the missing schema documentation.

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?

The description 'Ad spend history for a period' clearly identifies the resource (ad spend/costs) and the scope (a date period). However, it does not explicitly distinguish itself from similar siblings like wb_advert_payments or wb_advert_stats, so it falls short of 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?

There is no guidance on when to use this tool versus related alternatives such as wb_advert_stats, wb_advert_payments, or wb_finance_report. The description only states what the tool returns, not the context or exclusions that would help an agent choose correctly.

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