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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It explicitly states the pay-per-call cost ($0.05 USDC on Base via x402) and the error behavior when the payment-signature header is missing (error data carries payment terms). This is high-value context not visible in the schema and goes beyond typical descriptions.

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 sentences, each earning its place: purpose, return breakdown, and payment/error behavior. It front-loads the core purpose before covering operational details, with no filler or repetition.

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?

Given the tool's simplicity (2 params, no output schema, no annotations), the description covers the essential return fields and payment nuances. It lacks a concrete output example or interpretation guidance, but for a scoring tool the description is sufficiently complete to let an agent call it correctly and understand the result shape.

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 schema already describes 'query' and 'context' adequately, and the description does not add new parameter-level meaning beyond restating that content is scored. It does not explain how query/context interact or expected format, so no bonus beyond baseline is earned.

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 a specific verb and resource: 'Score the viral potential of content.' It then lists the return components (virality score, breakdown by emotion/specificity/novelty/shareability, platform recommendation), which clearly differentiates it from siblings like analyze-marketing-trends or extract-pain-points. No ambiguity about what the tool does.

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 explains what the tool does and mentions payment details, but gives no guidance on when to choose this tool over alternatives, nor any exclusions or prerequisites beyond the payment header. With 25 sibling tools, the lack of routing context leaves the agent to infer usage scenarios on its own.

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