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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds that it selects the lowest-friction option and returns exact price and resource URL, which is useful beyond annotations. However, it does not mention whether recommendations are stable across calls or how 'lowest-friction' is determined.

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?

A single, front-loaded sentence that includes the verb, resource, selection criterion, and return fields. No wasted words.

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?

The description is complete enough for a read-only recommendation tool with annotations covering safety and a fully documented parameter. It lacks sibling differentiation, but the core purpose and output are clear.

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%, and the single 'task' parameter is fully documented in the schema. The description adds no additional parameter semantics, so the baseline of 3 is appropriate when the schema does the heavy lifting.

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 (recommend) and resource (InstaVeil paid x402 product) with the outcome (exact price and resource URL). It is clear what the tool produces, but it does not explicitly differentiate itself from siblings like list_paid_products or get_product, which could also surface product listings.

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 does not explain when to use this tool versus alternatives such as list_paid_products, get_product, or get_purchase_instructions. It only states the purpose, leaving the agent without routing guidance.

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