Creative statistics

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

Annotations already declare read-only/idempotent, so the bar is lower. The description adds substantial context: output shape, metric list, money in rubles, inclusive 100-day period cap, absence of campaign totals, and API point cost with quota refill timing.

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?

Dense but remarkably efficient: the first sentence states purpose and output, and every subsequent clause adds operational detail (date limits, API cost, alternatives). Slightly long but not wasteful for the amount of critical context.

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?

Even without an output schema, the description fully specifies the return array structure, field names, metric breakdown, and constraints. Together with the annotations, it gives the agent everything needed to select and invoke the tool 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 coverage is 100%, so baseline is 3. The description adds meaning beyond the schema by clarifying creativeIds narrows and is required, relating dates to inclusive 100-day periods, and noting metrics are in rubles. It also ties parameters to workflow (get ids from list_creatives).

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: 'Per-creative statistics for the creatives you name in one campaign.' It distinguishes from siblings by noting this tool narrows to named creatives and that campaign_stats carries the same breakdown.

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 explains when to use: creativeIds is required, this tool narrows rather than enumerates; use campaign_stats for the whole campaign; prefer one wide period over many narrow calls due to API point costs. Also references list_creatives to obtain ids.

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