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

Annotations already establish readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description contributes genuinely new behavioral context: the data's provenance (official Census Bureau), the measure basis (origin of movement), and the exact time windows covered (last full year plus year to date). It omits any statement about freshness, refresh cadence, or what happens for territories with limited data, which keeps it from a 5.

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?

It is a single front-loaded sentence that leads with source and scope before listing returned fields, with no redundant or filler wording. The list of measures is dense but each item earns its place by telling the agent what output to expect in the absence of an output schema.

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 one-parameter, read-only lookup with no output schema, the description does the necessary work of enumerating return content (totals, rank, top destinations and products) and the time horizons. What is missing is only the sibling-routing guidance, which matters here because of the adjacent get_us_export_markets 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?

With 100% schema description coverage on a single required parameter, the schema already explains that 'state' accepts a two-letter code or full name, including examples. The description adds only the constraint that exactly one state or territory is covered per call, which is useful but marginal. Baseline 3 is appropriate when the schema does the heavy lifting.

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 (official U.S. Census Bureau export statistics for one state/territory, origin-of-movement basis) and enumerates the returned measures: total exports last full year and YTD, state rank, top destinations and products. That is far more than a restatement of the name. It stops short of 5 because it never distinguishes itself from the close-sounding sibling get_us_export_markets, which an agent could easily confuse with the destination-countries portion of this output.

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 agent can infer this is the tool for state-level export totals, but the description gives no explicit when-to-use trigger, no exclusions, and never names an alternative such as get_us_export_markets or find_us_exporters. Nothing is misleading, but the routing decision is left to inference.

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