How to get a full trust report

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds non-obvious behavior: the tool explicitly does NOT buy the report, payment happens via any x402 client, and unmonitored endpoints return 404 and are never charged. These are valuable operational disclosures beyond the annotations, though rate limits or timeout behavior are unmentioned.

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?

Key facts (what it returns, that it doesn't purchase, when to use it) are front-loaded, and the trailing link is useful. The sentence enumerating other paid checks is somewhat tangential but still helps an agent understand the payment ecosystem, so it mostly earns its place.

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 compensates by specifying the return payload (report URL, price, network) and by covering payment mechanics, failure mode (404), and usage gating. Nothing an agent needs to call this correctly is missing.

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 single url parameter is fully documented, so the schema does the work. The description only implicitly constrains it to monitored x402 endpoints, adding minimal meaning beyond the schema. Baseline 3 is appropriate.

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 states a specific verb and resource and immediately corrects the misleading name: it returns instructions/URL/price for a paid report rather than the report itself. It also contrasts with the free sibling check_endpoint, so an agent can route correctly without opening a 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 gating is given: 'Use it only when the free check_endpoint result isn't enough and the user wants the full history.' It names the alternative tool and the condition that selects it, leaving little to inference.

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