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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description does add useful behavior beyond that: results are ranked by fit to goal, a made_recently flag means the brand already used that look so prefer another, and next_page indicates the next call. It does not state page exhaustion behavior or result ordering ties, so it's solid but not rich.

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 core routing information is front-loaded and the URL fallback is a useful closing line, but the fragment-heavy, metaphor-laden style ('Styles sit on section shelves', 'put its id in the create_campaign brief (asset_type card)') reads more like marketing copy than instructions. Several clause fragments could be consolidated without loss.

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 7 optional parameters, a full output schema, and complete schema descriptions, an agent has everything needed to call this correctly, and the description covers the non-obvious parts (ranking, made_recently, pagination, the bulk-file alternative). The only gap is that it never explains what a page looks like when filters exhaust results.

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 the baseline is 3, but the description adds meaning the schema lacks: how goal actually affects output (ranks by fit), that section is the 'shelf' to take from the top, and that made_recently should steer you to another style. It also implicitly recommends section+page over setting all=true, which the schema only weakly hints at.

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 opens by naming the resource and its unit of iteration ('the still style library, one ranked page at a time') and defines what a style is with concrete examples (ad creative, poster, release card, App Store frame). It is clearly a listing/browsing tool, distinguishable from siblings like create_campaign or list_media, though the metaphorical phrasing ('Styles sit on section shelves') adds a little decoding effort.

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?

It gives real selection guidance: pass section plus the human's goal and take one from the top, and it routes the agent to create_campaign (asset_type card) once a style id is chosen. It also offers an alternative to paging entirely (the styles.md file), which is a genuine when-to-use-this-vs-that hint. What's missing is an explicit exclusion — e.g., when not to browse and instead search or read the file.

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