sign_and_pay

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

No annotations are provided, so the description carries the full burden and does so well: it discloses the irreversible side effect (real on-chain broadcast), the missing outcome (no VPN credentials fetched), the required follow-up call, and the double-charge failure mode. These are precisely the behavioral traits an agent cannot infer from the schema.

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 tight sentences, warning first, recommendation second, mandatory follow-up third. No filler, and the highest-risk information (DEBUG ONLY, double charge) is front-loaded.

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?

With no output schema, the description usefully names the returns (payment_signature, settlement_tx) and the required continuation, which is the critical path context for a payment tool. The remaining gap is parameter-level detail for a 0%-coverage schema, notably dry_run.

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 description coverage is 0% and the description only indirectly touches one parameter, the invoice_no that must be reused in fulfill_payment. The nested 'accepts' array structure, dry_run, and network are not explained anywhere, so the description only partially compensates for the coverage gap.

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 and resource ('Broadcasts on-chain payment') plus concrete return values, and immediately marks it as DEBUG ONLY, which distinguishes it from the sibling buy_vpn. An agent can tell what it does and what it is not for without opening the schema.

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?

Explicit routing: 'Prefer buy_vpn', plus a mandatory next step ('you MUST next call fulfill_payment with the same invoice_no') and two named prohibitions (never curl /pay, never call buy_vpn again due to double charge). This is exactly the when/when-not/alternatives guidance the dimension asks for.

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