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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds genuine behavioral context beyond that: the 90-day lookback window for brand videos and the explicit null return when the brand has no videos, which an agent could not infer elsewhere.

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 tightly packed sentences with zero filler; the default output is front-loaded and the conditional compare behavior follows. Every clause carries distinct information.

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 and no parameter descriptions, the description does well by naming the compare return fields and the null case, but it does not spell out the shape of the default (non-compare) benchmark response or what brandId defaults to when omitted.

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 0%, so the description must carry the burden. It fully explains `compare` including the field list of the returned `brand` object, but `brandId` is never mentioned, leaving one of two parameters semantically undocumented.

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 (Get) and resource (niche benchmarks) and enumerates the exact statistics returned (median/p75/p90 views and engagement). This clearly separates it from performance-oriented siblings like get_metrics_daily or get_top_performers.

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 compare=true behavior is described, giving implicit guidance on when the extra brand-relative output is produced. However, there is no explicit statement of when to prefer this tool over alternatives such as get_performance_summary or get_top_performers, and no prerequisites are stated.

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