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 states 'Discover' suggesting a read-only operation, and 'pay-per-request' hints at potential cost, but it does not explicitly confirm safety, rate limits, authorization requirements, or what happens upon invocation (e.g., whether it returns a list or single item). The behavioral transparency is minimal.

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 sentence that front-loads the key purpose and scope. Every word contributes value, and there is no redundancy or unnecessary detail. It is optimally concise for a tool with no parameters.

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 tool has an output schema but the description only hints at output content ('price, availability'). It does not explain what 'x402 APIs' are, how the results are structured, or whether pagination or filtering exists. While the tool is simple, the lack of output context leaves the agent partially informed. Completeness is adequate but not thorough.

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 input schema is trivially complete (100% coverage). The description adds no parameter information because none is needed. Per guidelines, zero parameters warrants a baseline of 4, and the description does not detract from this.

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 uses a specific verb 'Discover' and clearly identifies the resource 'Animica's pay-per-request x402 APIs (USDC on Base)' with details on what it provides ('price, availability'). This distinguishes it from sibling tools like animica_credit_balance or animica_ai_ask, as it focuses on x402 product offerings.

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 provide any guidance on when to use this tool versus alternatives. With 20 sibling tools, the lack of explicit when-to-use or when-not-to-use instructions leaves the agent to infer context without support.

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