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

No annotations are provided, so the description carries the full burden. "Aggregate figures" implies a non-mutating read over existing partner data, which is useful implicit context, and the metric list indicates the return content. However, nothing is said about permissions, data freshness, caching, or cost of the aggregation.

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 sentence, front-loaded with the core noun phrase "Aggregate figures:" followed by a scannable list of the aggregated dimensions. No filler, no redundancy.

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 and no parameters, the description is the only spec, and it only gestures at the metrics (e.g. "pricing transparency", "AI-assisted delivery") without defining what those aggregate values are or whether grouping/filtering is possible. It is enough to identify the tool but thin for interpreting results.

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 there is nothing for the description to disambiguate; the baseline for 0-param tools applies. The enumerated metrics give the agent a rough sense of the shape of the result, though no input surface exists to clarify.

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?

"Aggregate figures: partners per country and tier, medians per tier..." identifies a clear resource (aggregate partner statistics) and enumerates the dimensions it covers, which distinguishes it from the sibling lookup/search/match tools. It never states a verb like "returns" or "computes", but the intent is unambiguous.

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 guidance on when to use this versus get_partner, match_partners, or search_partners. The description only lists the metrics produced, leaving the agent to infer that this is the right tool when summary numbers (not individual records) are needed.

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