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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), but the description adds a genuinely valuable behavioral trait: the call is paid ($0.001, x402). Cost/payment requirements are exactly the kind of context annotations do not convey, so this earns meaningful credit.

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 tight sentences with no filler, and the primary purpose is front-loaded before the cost note. Efficient and appropriately sized for the amount of content.

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 7 parameters, 57% coverage, and no output schema, the definition is only minimally complete. It does not describe the result shape beyond 'source document and license', does not explain the limit/pagination behavior, and provides no guidance on how the filters combine.

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 description coverage is 57%. The description touches the main filters (quantity, family, unit, value range, source document words) and roughly mirrors the schema's own examples, but it adds no format or semantic detail beyond the schema and omits limit entirely, so it hovers at the baseline.

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 a specific resource (a structured specification table) and enumerates the filter dimensions (quantity, unit family, unit/value range) plus returning source document and license. It is clear what the tool does, but it never distinguishes itself from the sibling search_specs, so an agent cannot tell the two apart without opening both schemas.

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?

There is no when-to-use guidance, no statement of prerequisites, and no mention of the sibling search_specs as an alternative. The only routing-adjacent information is the paid price, which tells the agent nothing about when this tool is the right choice.

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