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

Annotations already declare read-only, idempotent, non-destructive, and closed-world behavior, so the safety profile is covered. The description adds useful context beyond annotations: the scope (historic announcements only, not current rate) and the returned fields (announcement number, effective date, previous/new percentages), which matters since no output schema exists.

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?

Two compact sentences with no filler; the scope and the historical caveat are front-loaded before the returned-field list. Efficient, though the field enumeration is slightly list-like.

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 single-parameter, no-output-schema read tool with annotations covering the safety profile, the description is largely complete: it explains scope, historic nature, and returned values. Only minor detail on the parameter format 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 description coverage is 0% for the single hs_code parameter, so the description must compensate. It partially does by noting the parameter is an HS code prefix, but it omits format details (the schema requires 4-10 digits) and does not name the parameter explicitly.

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+resource: changes in tracked Chinese export rebate announcements, scoped to an HS code prefix, returning announcement number, effective date, and old/new percentages. It implicitly distinguishes itself from rate-lookup siblings by clarifying it is historical rather than current. Clear, though it does not name the sibling tool that provides the current rate.

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 line 'This historical announcement lookup is not the current rate' gives clear context on when this tool applies and warns the agent off using it for live rates. It stops short of naming the alternative tool (e.g. find_duty_rate) explicitly, so it is strong context without full exclusion/routing guidance.

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