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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile needs no restating. The one genuine addition is 'computed live', which tells the agent the figures are not cached and reflect current data. With no output schema, the description does describe the return shape (the enumerated figures), which is worth credit, but it says nothing about cost, response size, or shape of the aggregate values.

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?

A single front-loaded sentence that leads with the value proposition ('Headline figures computed live from the atlas') before the enumeration. The final clause about productions recorded only at country level is informative but slightly convoluted; still, every clause maps to a returned figure, so there is no filler.

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 zero-parameter, no-output-schema aggregate tool, the description adequately discloses what comes back by listing each figure category. The main residual gap is that it does not indicate relative cost or whether the result is a single object keyed by metric, but that is minor given the simplicity of the 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?

The tool takes zero parameters, so per the baseline rule this scores 4. The description correctly implies a parameterless call by framing the result as fixed headline figures rather than something that can be filtered.

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 resource (headline figures) and enumerates the aggregates returned: totals by medium, by kind of place, top countries, busiest/most famous locations, and unplaceable productions. 'Computed live from the atlas' signals it is an aggregate overview rather than a listing. It does not explicitly distinguish itself from sibling top_locations, which overlaps with the 'busiest and most famous locations' figures.

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: the phrase 'headline figures' suggests an overview/orientation call, but there is no explicit 'use this when' statement, no exclusions, and no pointer to top_locations or search_locations for drill-down. An agent must infer the routing decision from the content rather than being told.

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