Add Watermark

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

Annotations already indicate a non-read, non-destructive operation. The description adds valuable transparency by specifying the async submission behavior, that the watermark content is server-fixed, and that the response yields a request_id for polling. It does not detail side effects (e.g., whether the original is modified) but covers the key operational traits.

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 concise and well-structured: a single purpose statement, two clarifying constraints, and a clean parameter list. Every sentence adds value without redundancy.

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 tool with two parameters, the description covers the async workflow, the request_id polling mechanism, and the param requirement. It does not explicitly describe the result format, but given the async pattern and the presence of a polling tool, this is sufficient for an agent to invoke and follow up.

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 is empty, so the description is the sole source of parameter information. It clearly defines image_url and video_url with types, optionality, and the critical constraint that exactly one is required. This fully compensates for the schema gap.

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 clearly states the specific operation: 'Apply the XBrush watermark to a target image or video.' This uses a strong verb ('apply') and explicit resources (image/video), making it distinct from sibling tools like generate, upscale, or remove_bg.

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?

Provides usage context by explaining the async workflow ('poll the returned request_id with xbrush_get_request') and the limitation that the watermark is fixed with no customization, implicitly guiding against use for custom watermark needs. However, it does not explicitly contrast with alternatives or state when to prefer this tool over others.

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