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

Annotations already declare readOnly/idempotent/openWorld, yet the description adds real behavioral caveats an agent cannot infer: coverage is partial, empty candidates never establish clearance, and unknown/different-country evidence is retained in comparisons. It also enumerates what is deliberately out of scope (applicability, stacking, combined duties), which prevents over-trusting the output.

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?

Front-loads the action and its input constraint, then the caveats; nearly every sentence carries distinct information. Density borders on cryptic ('unmapped views', 'different-country evidence') and could be slightly more readable, but nothing is padded.

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?

With a full output schema and rich annotations, the description covers domain limits, coverage gaps, and mode selection adequately. Paging behavior and return shape are handled by the schema, so remaining gaps are minor; a brief note on what a candidate result means for follow-up would make it complete.

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%, so the parameters are already fully documented structurally. The description only restates the candidateCode/noteId/noteCursor constraints already present in the schema, adding no syntax, format, or edge-case value beyond it.

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 ('Find Chapter 99 candidate headings and source references') scoped to an exact eight- or ten-digit commodity number. The closing disclaimer ('No applicability, current legal status... are determined') implicitly separates it from the duty-rate and search siblings, though no sibling is named directly.

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 concrete selection guidance across the three modes ('Use candidates, evidence with a returned candidateCode, or unmapped views') and a workflow instruction for noteId/noteCursor. It omits an explicit 'use this instead of usitc_lookup_duty_rate / usitc_browse_chapter' routing statement, so the alternative-selection half is missing.

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