Fetch x402 Resource (auto-pay)

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

Annotations already indicate a destructive, non-read-only, non-idempotent operation, but the description adds critical behavioral detail: the automatic payment from the wallet, the hard cap via maxSats, spend policy enforcement, network/scheme limitations, and the honest handling of unsupported networks. This goes well beyond the structured hints and gives the agent a clear safety model.

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 well-structured with a clear first sentence, a 'Safety' section for critical constraints, and a compact 'Args/Returns' listing. Every sentence earns its place, and the front-loaded purpose makes it easy to scan. It is detailed yet concise, with no filler.

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 no output schema, the description provides a clear return structure ({ status, body, paid?, receipt? }) and covers the main behavioral outcomes (pay vs. no-pay, success conditions, unsupported scenarios). For a tool with payment side effects, this is a complete and usable description without needing extra context.

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 all parameters have descriptions, so the baseline is 3. The description adds value by framing maxSats as an 'agent-set budget' and emphasizing it is REQUIRED, which reinforces its role as a safety guard. It also clarifies the method default (GET) and the purpose of the URL, but these mostly mirror the schema, so a 4 is appropriate rather than 5.

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 precise verb ('Consume') and a specific resource ('x402-paywalled resource'), then clearly outlines the one-call workflow: detect 402, pay, retry with proof, return resource + receipt. It also distinguishes itself from siblings like ordnet_x402_quote by emphasizing the auto-pay/consume action.

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 clearly states when to use the tool (to consume a paywalled resource in one call) and gives important constraints: maxSats is required, only 'exact' scheme on 'bsv' is supported, other networks are reported unsupported, and non-paywalled URLs are fetched without payment. However, it does not explicitly name the alternative for quote-only usage (ordnet_x402_quote), so it misses an explicit when-not-to-use reference.

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