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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds the metric set and the 'versus category peers' comparison angle, but says nothing about date-window semantics, freshness, or result volume beyond what the annotations/schema imply.

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 front-loaded sentence that packs the resource, the two scoping dimensions, and the metric list without waste. It is efficient, though the metric enumeration is dense and could have been trimmed in favor of routing 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 an output schema present, return values need not be described, and annotations carry the safety profile, so the description is adequate. The remaining gap is routing context against sibling performance tools, which the description never addresses.

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 all 12 parameters are already documented with ranges, defaults, and LIKE-match semantics. The description only alludes to brand and category scoping and does not add syntax or default behavior beyond 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 (Get) and resource (Amazon Ads Brand Metrics health), scoped by brand and category, and enumerates the metrics returned. It does not differentiate itself from siblings like get_share_of_voice, get_brand_search_terms, or get_campaign_performance, so an agent must infer the boundary.

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 when-to-use guidance, no indication of when this differs from adjacent Brand/campaign performance tools, and no noted prerequisites or caveats. The agent gets no routing help for choosing among the ~100 siblings.

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