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

Annotations only say readOnly/openWorld=false; the description adds the critical domain behavior that jurisdiction controls bind only with a nexus, and that each response carries a payment_jurisdiction_note explaining applicability. That is genuine behavioral context an agent cannot get from the annotations or schema.

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?

Well front-loaded: purpose, returns, then the nexus caveat, then examples. The IMPORTANT paragraph restates the payment_jurisdiction_note point already made one sentence earlier, and the four example lines are somewhat redundant, so it is slightly longer than strictly needed.

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 two-parameter lookup with an output schema already declaring return shape, the description supplies everything else an agent needs: scoping semantics, the nexus rule, filter usage, and worked examples. Nothing material is missing.

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 coverage is 100% so the baseline is 3, but the description goes beyond the schema by explaining when to supply jurisdiction (only when you know the payment's actual touchpoints) and by giving multi-example invocations including the two-argument form. The added semantics justify a 4.

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 and resource ('Look up export control restrictions for a specific country') and enumerates the returned data (embargo status, sanctioned programs, control reasons, jurisdictions). It never names the closest sibling, export_controls_screen, so an agent cannot rule that tool out from this description alone.

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?

Gives a clear when-to-use trigger ('What export restrictions apply to shipping to Russia?'), a parameter-selection rule for the jurisdiction filter, and an explicit when-not ('do NOT cite US controls without confirming a US nexus'). It stops short of routing between this and sibling tools like export_controls_screen or sanctions_screen.

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