qm_data_iss_pass

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

With no annotations, the description carries the full burden and does so: it discloses the exact cost ($0.01 USDC on Base via x402), the two-phase handshake, that the tool never pays and never touches private keys, and that the server only forwards the payload. These are precisely the trust and custody facts an agent needs before committing a payment flow.

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?

Front-loaded with what the tool is and its cost, then the workflow, then the no-custody caveat. It's dense but each sentence does work; the trailing example partly repeats the second-call explanation already given.

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 paid two-phase tool with no output schema, the payment mechanics and result location ("the passes come back in the tool result") are covered. The shape/fields of the returned pass predictions are not described, which is the one remaining gap an agent might want.

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 the 'payment' parameter's schema text already says to omit it on the first call and supply the base64 x402 payload on the second, so the description largely restates it. The example coordinates add marginal concreteness but no meaning beyond the schema; baseline 3 applies.

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 ("ISS pass predictions") plus cost, rail, and data source, which no sibling like qm_data_astronomy or qm_data_weather covers. An agent can immediately tell what this returns and under what billing model.

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 two-phase protocol is spelled out concretely: first call with lat/lon and no 'payment' returns payment requirements, then re-call with the signed payload. What's missing is routing guidance against alternative astronomy/data tools, so it stops just short of a 5.

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