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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so safety is covered structurally. The description adds the non-obvious behavioral trait that this returns only a preview (dimensions + "latest few values") rather than the full data, which is real context beyond the annotations. It doesn't mention rate limits or sampling window specifics, so not a 5.

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 sentences with no waste: sentence one lists outputs, sentence two gives placement and purpose. Front-loaded and appropriately sized for a two-parameter read tool.

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 returns and does so reasonably (dimensions, default series, latest few values). It is slightly incomplete on how many values constitute "latest few" and on behavior when country is omitted, but it is adequate for a read-only preview tool.

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 100%, so both id and country are already documented, giving a baseline of 3. The phrase "for a country" reinforces that country scopes the sample, but adds no syntax or default behavior beyond the schema's "Optional country, e.g. 'France'."

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?

States a specific verb ("Show") and resource (one dataset) and enumerates what is surfaced: dimensions, default series, and latest values. It implicitly separates itself from get_series by framing it as a fit-check before "pulling the full series," but never names get_dataset or get_series directly, so sibling differentiation is partial.

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?

Gives explicit sequencing guidance ("Use after search_catalog") and the purpose condition ("check the dataset fits before pulling the full series"), which routes the agent well. It stops short of naming when-not-to-use or the explicit alternative tool for the full pull.

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