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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context: guaranteed no input, no network request, and no payment/charge, which is exactly the cost-risk information an agent needs before calling.

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?

A single tight sentence with the key qualifier ('Free') front-loaded. There is mild redundancy between 'Free' and 'no payment', but no filler otherwise.

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 must convey what comes back, and it does: prices of paid tools and endpoints plus the payment network and address. It is complete for a zero-arg introspection tool, with only minor ambiguity about the exact return shape.

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?

There are 0 parameters, so the baseline is 4. The description confirms 'No input', reinforcing that this call is argument-free, but there is nothing further to document.

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 the resource precisely: prices of the paid tools and HTTP endpoints, plus the payment network (Base) and receiving address. An agent can distinguish this metadata tool from siblings scan_site and full_report, though the verb is only implied rather than stated (it reads as a noun phrase with no 'returns'/'gets').

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?

'Free' and 'No input, no network request, no payment' imply this is a zero-cost discovery call, which suggests calling it before invoking paid tools. However, it never explicitly says when to use this versus the siblings or that it should be used to check costs before a paid call.

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