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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false), so the description's added value is the state machine: pending, success with image_url ready, or failed with credits refunded. The refund-on-failure detail is real behavioral context an agent could not infer from structured fields. It omits whether repeated polling is expected or whether task_ids expire.

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?

Two short sentences, front-loaded with the operation and followed by the outcome states. Every clause carries information; nothing is padding.

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 one-parameter polling tool with annotations covering safety and no output schema, the description supplies the essential missing piece: the possible statuses and their meanings including the credit refund. Only the polling/expiry behavior is left unstated.

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 parameter's schema description already says it is the task_id returned by create_image or restore_photo, which the prose merely echoes. No additional format or lifetime guidance is provided, so the 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?

The description names a specific verb ("Check") tied to a specific resource ("an image task"), and scopes it to tasks produced by create_image or restore_photo. That implicitly separates it from get_video and the creation tools, but it never states the contrast outright.

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?

"Check an image task from create_image or restore_photo" gives a clear usage context: call this after starting one of those two jobs. There is no explicit when-not guidance or named alternative (e.g. get_video for video jobs), so it falls short of a 5.

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