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

With no annotations, the description carries the full burden and usefully discloses the auth profile: no account, no signup, no key required. This is real behavioral context an agent needs before calling. It stops short of covering rate limits, response format, or whether the data is static — acceptable for a zero-parameter info tool.

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?

Two short sentences with the payload (what terms are returned) front-loaded. The second sentence slightly overlaps ideas – 'no account or signup', 'free', 'works without a key' restate the same no-auth point with some redundancy.

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?

No output schema exists, but the description enumerates the returned fields (asset, network, address, prices, claim instructions), so an agent knows what to expect. For a zero-param informational tool with no annotations, this is nearly complete; sequencing relative to payment/screening siblings is the only missing piece.

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?

The tool takes zero parameters, so the baseline is 4. There is nothing for the description to compensate for, and the schema is empty as expected.

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 names a specific resource – machine-readable payment terms – and enumerates its content (asset, network, address, per-operation prices, API key claim). It clearly distinguishes this informational tool from operational siblings like onyx_screen or onyx_watch, though it never states the verb explicitly (e.g., 'returns'/'fetches').

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?

It implies the tool is the entry point for payment/key acquisition ('how to claim an API key'), but gives no explicit when-to-use-vs-alternatives guidance or sequencing (e.g., call this before onyx_screen). Usage is left to inference from the sibling set.

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