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

No annotations are provided, so the description carries the burden. It discloses the paid nature, the requirement to call without x_payment to receive terms, sign them, and call again with x_payment. This is strong transparency for a paid tool, though it doesn't mention error behaviors or return format.

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?

Three sentences, each earning its place: resource overview, usage pattern, and payment flow. No fluff or repetition, and the most important usage guidance is front-loaded.

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 simple tool with two optional parameters and no output schema, the description covers the key aspects: what data is available, how to list/fetch, and how payment works. It could mention the response format or whether data is historical, but the tool is adequately specifiable as-is.

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 both parameters have descriptions. The description adds value by explaining the payment sequence associated with x_payment and the optionality of id, complementing the schema's details.

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 identifies the resource (US macroeconomic series) and the actions: pass an id to get one series or omit to list available ones. It differentiates from sibling tools by naming the free `pricing` tool for all prices at once.

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?

Explicitly explains when to use the tool: pass an id for a specific series, omit to list. It also provides a clear alternative ('The free `pricing` tool lists every price at once') and details the two-step payment flow, which is crucial for correct invocation.

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