Upscale Image

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

The description reveals the tool's asynchronous nature and the need to poll for the result, information not present in the annotations. This is key behavioral context beyond the readOnly/destructive hints, though it could mention failure or polling specifics.

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?

The description is three short, high-signal sentences: purpose, async note, and args. No filler or redundancy; all content earns its place.

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 simple async tool, the description covers the essential usage loop: call, receive request_id, poll. It lacks response structure or error details, but that is handled by xbrush_get_request. The description is sufficiently complete given the tool's simplicity and sibling relations.

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?

The input schema already fully describes both parameters with constraints and defaults. The description's Arg list repeats this information without adding new meaning, so it neither improves nor harms parameter understanding.

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 opens with 'Upscale an image to higher resolution,' a clear verb+resource+outcome statement. It also notes async submission, which distinguishes it from synchronous sibling tools like xbrush_image_generate and xbrush_image_edit.

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 provides explicit workflow guidance ('Submits async — poll the returned request_id with xbrush_get_request'), implying how to use the tool. However, it does not name alternative tools or state when not to use this tool, leaving the usage context partially implied.

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