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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real behavioral context beyond that: the status lifecycle values (pending, processing, completed, failed), the 'thumbnail when ready' timing caveat, and the cost signal 'Costs no credits'. Return format details are largely deferred to the output schema.

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?

Three short sentences, front-loaded with the resource and its fields, then scope, then the polling role. Dense with signal and no filler, though the field enumeration slightly overlaps the output schema.

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?

Given a rich output schema and covering annotations, the description only needs to add selection context, which it does via the polling relationship and credit cost. Nothing an agent needs in order to call this correctly appears to be missing.

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 a single documented parameter ('The influencer id from list_characters'), so the schema does the heavy lifting. The description implies the id targets an influencer but adds no syntax or format detail beyond what the schema already states; 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 and resource ('The looks (reference images) of an AI influencer') and enumerates what is returned (id, status, scene_prompt, thumbnail). It also positions itself relative to create_character and generate_image, which helps distinguish it, though it never explicitly contrasts with the closest siblings like list_characters or list_videos.

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?

Explicitly says it is 'the poll call for create_character and generate_image', which tells the agent exactly when to reach for it, and clarifies it works for both the user's own influencers and the public cast. There is no explicit when-not guidance, but the context is clear.

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