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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds a useful hint about what comes back (versions plus the rendered image), but says nothing about cost, size, or failure behavior for a missing/inaccessible id.

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 fragment with no waste; the key noun and scope come first. It is terse to the point of being slightly informal ('the picture itself'), but nothing is redundant.

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 annotations covering safety, a fully documented two-parameter schema, and an output schema for return shape, the description needs only to state scope. It does that plus a brief payload hint, leaving only edge cases (unknown id, missing brand) unaddressed.

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% with both parameters documented, including the fallback behavior for brandId ('read from the id when omitted'). The description adds no parameter meaning beyond the schema, so 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 resource (one creative by id) plus notable payload content (versions and the image itself), which distinguishes it from list_creatives and get_creative_insights. It never names a sibling explicitly, so differentiation is inferred from the 'one ... by id' scope rather than stated.

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 only implied: 'one creative by id' signals single-record retrieval versus the list/search siblings, but there is no explicit when-to-use or when-not-to-use guidance. The schema's creativeId note (ids come from list_creatives, search_library, get_job, get_upload) does the routing work rather than the description.

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