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

Annotations already cover readOnly/idempotent/non-destructive, but the description adds genuinely new behavior: reads stored database state rather than polling the image provider, credits_remaining is surfaced at top level, and success yields a temporary download_url with an expires_at. That is meaningful context beyond the structured fields.

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 tight sentences, each carrying distinct information: what is read and in what states, the polling cadence and its non-provider side effect, and the shape of a successful result. 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?

For a single-parameter read tool with a full output schema, the description covers the remaining unknowns an agent needs: polling cadence, terminal states, and the fact that reads hit the database rather than the provider. No critical gap remains.

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% and the single task_id parameter is fully documented in the schema (UUID format, pattern, origin). The description adds no syntax or format detail beyond that, 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?

States a specific verb and resource ('Read an account-owned task') plus the exact set of valid states (pending, processing, succeeded, failed), which pins down what the tool returns. An agent can distinguish it from upscale_image (which creates tasks) and get_upscale_info without opening the 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?

Gives explicit operational guidance: repeat the call roughly every 5 seconds until the task reaches succeeded or failed, i.e. it is the polling endpoint for a created task. It does not name get_upscale_info or upscale_image as alternatives or state when not to use this tool, so it stops short of full routing guidance.

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