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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds that it is public (no key needed) and outlines the scope of information returned. It also explains the charging model (full charge at launch), which is domain context, not tool behavior. No contradictions, and it adds value beyond the annotations.

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 description is a bit dense but every sentence earns its place: it covers the price structure, charging model, fee details, top-up rules, sandbox behavior, public access, and a usage directive. The core purpose is front-loaded ('The price list as data'), and it remains readable despite the breadth.

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 0-parameter tool with an output schema, this description is complete. It tells the agent what the tool returns, that it's public (no auth needed), and that it should be called first. The output schema handles the exact return structure, so nothing needed for correct invocation 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 has zero parameters, and the schema description coverage is 100% vacuously. Per the rubric, 0 parameters earns a baseline of 4. The description does not need to explain parameters, and it doesn't.

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 clearly states the tool returns 'the price list as data' and enumerates its contents (pricing by size, fees, top-up rules, sandbox). It identifies a specific resource (price list) and a specific action (get), and the 'call this first' instruction helps distinguish it from related tools like quote_campaign.

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 explicitly says 'Call this first' and notes it's 'Public — no key needed', giving clear contextual guidance for when to invoke it. It does not name alternatives like quote_campaign, but the instruction to call it first serves as a de facto usage rule, making this a strong 4.

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