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

Annotations already declare readOnlyHint=true, so safety is covered; the description adds genuinely non-structured context by disclosing that a commercial API key is required and linking to the plan page. It does not say what happens on a missing/invalid key or how large the response can be, which is a notable omission for a 'full dataset' tool.

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 with zero filler; the data scope is stated first and the access prerequisite second. Nothing is repeated or wasted.

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 carries the burden of describing the return, yet it never says what a 'row' looks like, whether results are paginated, or how large the payload can get. For a full-dataset commercial endpoint, those details matter to an agent deciding whether to call it.

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 50%: country is well documented in the schema, while the topic enum has no per-value descriptions. The description adds that topic takes exactly one value and that country is optional, but contributes nothing about the 15 allowed topic values or accepted country formats beyond what the schema already says.

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?

"Every row of one topic, optionally for one country" states the retrieval scope precisely: a full, unfiltered row dump scoped by topic and optional country. It does not explicitly contrast with siblings like get_country_profile or compare_countries, so an agent must infer the difference, but the resource and granularity are clear.

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?

Usage is only implied: 'every row' suggests a bulk/full extract versus a summary tool, and 'optionally for one country' hints at scoping. There is no explicit statement of when to prefer this over get_country_profile or compare_countries, and no warning about when not to use it (e.g., for a narrow lookup).

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