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

With no annotations, the description carries the full load and does well: it discloses the model, output format/size, price, and a content-moderation gate that rejects sexual content, minors, and graphic violence before payment. It omits rate limits, latency expectations, and failure behavior, which keeps it below a 5.

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?

One sentence, front-loaded with the core action, then output format, then policy and price. Every clause carries information an agent would otherwise have to discover empirically.

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 3-parameter tool with no output schema, the description covers the return value shape (base64 JPEG at 1024x1024), the cost, and the moderation gate. What remains missing is error/payment-failure behavior, but the essentials for a correct first call are present.

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%, so prompt, steps, and payment are already documented in the schema, and the description adds only the $0.01 price beneath the baseline-3 expectation. It doesn't explain what the steps parameter trades off or clarify payment failure handling beyond the schema's own note.

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 (generate) and resource (image) plus the exact output format, resolution, model, and hosting provider. No sibling tool does image generation, so this is fully distinguishable from the surrounding catalog of market/wallet/x402 tools.

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 implies the usage context (text prompt in, image out, costs $0.01) but never states when to use this versus any alternative or what prerequisites apply. There is no sibling image tool to route against, which limits the practical harm, but the guidance is only implied.

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