zunivo_paid_fetch

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

With no annotations, the description carries full burden and does it well: discloses the automatic payment flow (USDC from agent wallet within budget), the 402 retry behavior, and the return payload including payment receipt. This is significant behavioral transparency.

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?

Three purposeful sentences, front-loaded with the core action and key differentiator. Zero waste.

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 5-parameter tool with no output schema, the description covers the essential behaviors and return values. It could benefit from mentioning error handling when budget is insufficient, but overall it provides enough context for correct invocation. Sibling tools cover agent discovery, so the integration is reasonable.

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 descriptions cover 80% of parameters, so baseline is 3. The description adds the key semantic that target can be either a full URL or an agent+path combo, which clarifies the relationship between url, agent, and path. This elevates it to 4.

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+resource ('Call a paid HTTP API') and the key differentiator (automatic payment on 402). Clearly distinct from sibling tools which manage agents/orders/payments.

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?

Provides clear context on when to use (calling a paid API, with auto-payment on 402) but does not explicitly compare with sibling tools or state exclusions. The target forms (full URL vs agent+path) add usage guidance.

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