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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, and the description does not contradict them. It adds minimal behavioral context beyond scope ('reported' totals), but does not say much about pagination or aggregate granularity beyond what the schema and annotations already imply.

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 states the action and scope with no filler. Every word contributes value.

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 simple, read-only, idempotent getter with zero required parameters, fully documented schema parameters, and an output schema, the description is nearly complete. It only misses explicit sibling routing guidance, which is partially covered by the 'global' scope.

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% and every parameter has a clear description with defaults, min/max, and constraints. The tool description adds only 'for a year,' which weakly reinforces the year parameter, so it matches the baseline 3 baseline.

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 uses a specific verb and resource: 'Return reported global merchandise-flow totals for a year.' The term 'global' clearly distinguishes it from sibling tools like get_country_trade, get_corridor_trade, and get_product_trade.

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?

The description gives clear context—this is the global aggregate view for a single year—so an agent can infer when it applies relative to country/corridor/product-scoped siblings. It does not explicitly name alternatives or exclusions, hence not a 5.

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