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

Annotations already declare readOnly, idempotent, non-destructive behavior, so the bar is lower; the description still adds real context by disclosing the lifecycle states (QUEUED | PROCESS | DONE | FAILED), the presence of an error field on failure, and that image_render_url with size and format only appears once DONE. It does not say whether polling is expected or whether both identifiers can be omitted, which keeps it from a 5.

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 dense sentence, front-loaded with a [read] marker and the resource, with the state enumeration and conditional return folded into parentheses. Zero filler, though the nested parenthetical makes it slightly harder to scan than a two-sentence split would be.

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 two-parameter read tool with full annotation coverage and no output schema, the description supplies everything essential: what it reads, which creators feed it, the complete status vocabulary, and what payload appears on success. Only the id-precedence detail is missing, which is minor at this complexity.

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 0%, so the description must carry the load. It does clarify that image_id and image_uuid are alternative lookup keys for the same asset, which is useful, but it omits which is required (both are nullable in the schema), precedence when both are supplied, and any format expectation for the UUID.

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?

Names a specific verb (retrieve state) and resource (a character image produced by the four create_* image tools), and enumerates the fields returned: track, error, image_render_url. An agent can immediately tell this apart from create_character_image or list_images without opening a schema.

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?

The description pins the tool's role to the outputs of create_character_image / create_character_thumbnail / create_replace_image / create_promo_image, which strongly signals it is the status-polling companion to those creators. It stops short of saying 'call this repeatedly until track=DONE' or naming what to use instead when you already know the image is finished (e.g. render_image), so there are no explicit exclusions.

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