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

With no annotations, the description carries the full behavioral burden. It discloses the content of the result set (exporters, importers, sectors, leading companies with USD totals), which implies a read-only informational tool, but it never states that it is non-destructive, whether data is a live or static snapshot, or what period the totals cover.

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, front-loaded with what the tool returns and followed by when to use it. No filler, no restatement of the title, and every clause adds information.

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 tool with no output schema and no annotations, the description does the necessary work of explaining what comes back (ranked companies, sector breakdowns, USD totals). The remaining gap is scope transparency: it does not say whether figures are current, historical, or an all-time aggregate, which matters for an overview 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 with 100% schema coverage, so there is nothing for the description to disambiguate. Baseline of 4 applies; no parameter meaning is missing because no parameters exist.

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 names a specific resource (Peruvian foreign trade) and enumerates the exact contents: top exporters and importers with USD totals, export sectors, and leading companies per sector. It does not explicitly contrast itself with siblings like peru_trade_by_country or peru_company_trade, but the 'overview' framing and content list give an agent enough to distinguish it in practice.

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?

It states a clear usage context: a starting point for exploring Peru's export economy or for finding leading companies per sector. There is no explicit when-not-to-use guidance or named alternative (e.g., 'use peru_company_trade for a single company'), so it stops short of a 5.

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