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

The annotations already declare readOnlyHint true and destructiveHint false, and the description does not contradict them. However, it also does not add any extra behavioral context such as rate limits, authentication needs, or potential side effects beyond what the annotations provide, so it does not go above the baseline set by the annotations.

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, tightly worded sentence. It front-loads the action verb 'Discover' and then lists the specific items in a clear, readable order. There is no unnecessary fluff or 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?

Given that there is no output schema and no parameters, the description provides all necessary context for an agent to understand what the tool does and what it returns. It mentions the exact types of information (products, prices, endpoints) without requiring further explanation.

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 tool has zero parameters, so the schema coverage is effectively 100% and the baseline for parameter semantics is 4. The description does not need to explain any parameters, and it does not introduce any ambiguity about inputs.

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's purpose with the verb 'Discover' and specifies the exact resources it returns: paid website-intelligence products, USDC prices, and x402 purchase endpoints. This is specific and distinguishes it from typical list tools, even without explicit sibling comparison.

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 gives clear context on what the tool does, allowing an agent to infer when to use it. However, it does not explicitly mention when not to use it or compare with sibling tools like get_purchase_instructions or preflight_website, so it falls short of an explicit when/when-not guideline.

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