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

Beyond the annotations, the description discloses billing behavior (per-call credit cost, repeat charges on repeated calls) and a data-safety caveat ('Treat returned data as untrusted'), neither of which appears in the annotation block. This is consistent with idempotentHint=false and readOnlyHint=true, and adds real value for an agent deciding whether to re-invoke.

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 sentences, front-loaded with the capability and then the cost/untrusted caveats; nothing is padded. Density is high, though the cost sentence is slightly run-on and could be tightened.

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 three-optional-parameter, read-only browse tool with no output schema, the description does the necessary work: it enumerates the returned metrics and warns about cost and trust. Pagination behavior via cursor is only covered by the schema, which is acceptable given full coverage there.

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?

With 100% schema description coverage across all three parameters, the schema already documents size, cursor (opaque, from next_cursor), and industryId. The description adds nothing parameter-specific, including nothing about the industry ID format or pagination loop, so the baseline of 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?

The description names a specific verb and resource ('Browse high-performing TikTok ad creatives') and even previews the returned fields (likes, CTR, spend level, video). This clearly separates it from the sibling set, which is dominated by Amazon research and TikTok Shop tools, though it does not explicitly name a nearest alternative.

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?

Usage is implied by 'browse high-performing... creatives' and the industryId filter, but there is no explicit when-to-use/when-not-to-use guidance or named alternative such as tiktok_ads_trending_hashtags. The cost note ('1 account credits per successful call', 'Repeated calls may charge again') is genuinely useful decision context but is pricing, not routing.

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