buy_capability

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

Despite no annotations, the description discloses key behaviors: automatic detection of free vs paid, verification of payment recipient, timeout returning job event ID, and conditional auto-pay. This adds significant transparency beyond 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?

The description is a single paragraph of four sentences, covering essential points without redundancy. It could be slightly more structured, but it remains efficient and focused.

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 the lack of output schema and five parameters, the description explains key behaviors and parameter usage adequately. It covers payment verification, timeouts, and auto-pay logic, though return structure on success is not detailed.

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?

With 0% schema description coverage, the description compensates by explaining the roles of provider_npub, capability, input, max_price_lamports, and timeout_secs in context. It clarifies the behavior tied to max_price_lamports, adding meaning beyond the raw schema.

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 action ('Buy a capability from an agent'), specifying the verb and resource. It distinguishes this tool from sibling tools like 'send_payment' or 'submit_and_pay_job' by focusing on purchasing a capability, which is a distinct operation.

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 provides explicit guidance on when to set max_price_lamports for auto-approval and explains the timeout behavior. However, it does not mention when to avoid using this tool or explicitly compare it to alternatives, though the context is clear.

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