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

Adds real context beyond the annotations: the $990 charge, that bad input is refused before any charge, the two acceptable payment rails, and that the tool returns a paid request rather than the data itself. Annotations already cover safety/idempotency, so this extra pricing and charge-timing detail is genuinely value-adding; it stops short of describing retries or failure modes after a charge.

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 most important facts (what it is, price, sibling difference) are front-loaded, but the text is redundant: '$990' and 'in one x402 payment' each appear twice, and the endpoint POST path is repeated. It is information-dense but not tight.

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?

There is no output schema, and the description compensates by stating the return is the paid x402 request plus a response schema and example, and by explaining the two-step pay-then-POST flow. That covers what an agent needs; only post-payment error behavior is unaddressed.

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%, so the parameters are fully documented in the schema and the enum for chain is given there. The description only adds that email is required for the check endpoint, which is marginal; baseline 3 is appropriate when the schema does the heavy lifting.

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 ('buy DAO treasury report, yearly') plus price and payment rail, and explicitly distinguishes itself from the sibling buy_dao_report ('Yearly plan; for one month use buy_dao_report'). An agent can select it without opening either 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?

Gives explicit routing for yearly vs monthly, describes the free pre-check path ('POST the same body to /buy/dao-report-yearly/check'), and states the workflow (POST body to URL with an x402 or MPP client to get data). Nothing is left to inference.

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