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

With no annotations, the description carries the full burden, and it does disclose that the result is a derived comparison metric ('unshipped balance') rather than raw contract or shipment rows. However, it says nothing about permissions, data freshness, whether both ESR and GATS must be available, or the result's granularity beyond that single aggregate.

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 that front-loads the comparison semantics and ends with the payoff metric. Every clause earns its place with 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?

Adequate but thin for a tool with no output schema and no annotations: the agent knows what is compared and one output field, but not the time window, aggregation level, or units of the 'unshipped balance'. Those gaps matter because nothing else in the definition fills them.

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 both parameters (commodity enum, partner country code) are documented in the schema, so the baseline is 3. The description adds no additional meaning about how commodity or partner affect the comparison.

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 (compare) and two named resources (ESR sales contracts, GATS actual shipments) plus the derived output (unshipped balance). It is clearly distinguishable from data-retrieval siblings like get_export_sales or get_trade_flows, though it never names an alternative explicitly.

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?

No guidance on when to reach for this comparison versus get_export_sales, get_trade_flows, or list_esr_commodities / list_gats_commodities. No prerequisites, no exclusions, no indication of the time scope of the comparison.

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