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

Annotations already declare readOnlyHint=true, so the description's 'Read-only; nothing is purchased' largely restates structured data, though it usefully clarifies there is no commercial side effect. With a zero-parameter tool and an output schema covering the return shape, the remaining behavioral burden is small.

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, zero filler, with the content of the listing front-loaded ahead of the safety note. Every clause 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?

For a zero-parameter, read-only lookup whose return values are fully specified by the output schema, the description covers purpose, scope, and side-effect profile. Nothing an agent needs in order to call it 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?

The tool takes no parameters, so the baseline is 4. The description adds the currency context (USD) about the returned data, which is the only semantic detail available for a parameterless call.

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 verb and resource ('List Brandize service tiers') and states exactly what is returned (price in USD and included features). No sibling tool covers pricing, so the boundary against the generation-oriented siblings (generate_logo, buy_logo_variation) is unambiguous.

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?

'Read-only; nothing is purchased' implicitly signals this is the informational lookup to use before or instead of a purchase action such as buy_logo_variation. It gives clear context for when the tool applies, but never explicitly names the alternative or an exclusion condition.

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