x402_image

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

Since no annotations are provided, the description carries the full burden. It does disclose the output type (PNG) and a key behavioral trait (cost of $0.05 USDC/call), but it omits other potentially relevant details like authentication requirements, rate limits, or non-deterministic generation behavior. This is adequate for a simple tool but not thorough.

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 a single, efficient sentence that front-loads the core action and includes the output format and cost. Every word carries value, with no redundant or tangential information.

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 one-parameter tool with no output schema and no annotations, the description covers the essential invocation context: what it does, what it returns, and what it costs. It does not explain selection among sibling tools, but that gap is already addressed under usage guidelines.

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 100%, so the baseline is 3. The description adds no meaning to the single 'prompt' parameter beyond what the schema already provides ('Image prompt'), relying entirely on the structured schema.

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 tool performs AI image generation and returns a PNG image, which is a specific verb+resource pair. It does not explicitly differentiate from sibling tools like x402_render or x402_screenshot, so it misses the top score for sibling distinction.

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?

There is no guidance on when to use this tool versus alternatives such as x402_render, x402_screenshot, or x402_video. The description gives no contextual conditions or exclusions, leaving the agent to infer when image generation is appropriate.

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