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

No annotations are provided, so the description must fully disclose behavioral traits. It does not mention whether the operation is read-only, error handling, pagination, auth requirements, or data limits. The description only states what it returns and the uniqueness of the data, leaving the agent without critical behavioral context.

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?

The description is two sentences long, front-loaded with the primary action and key differentiator. Every sentence provides value, with no redundant information or 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?

For a simple two-parameter read-only tool without an output schema, the description covers the purpose, unique value, and parameter requirements. It omits details about the result format or potential large response sizes, but the context is largely sufficient for a tool of this complexity.

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?

The schema already describes both parameters fully (hs8 pattern and since format). The description only repeats that hs8 is required and since is optional, adding no additional semantic meaning beyond the schema.

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 clearly states the tool returns the historical changelog of MFN duty rates for a Swiss customs tariff (HS8) code. It distinguishes itself from sibling tools like tariff_lookup by emphasizing the historical, archived nature of the data.

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 description provides clear context for use (historical data, irreplicable via scraping) but does not explicitly name alternatives or exclusion criteria. It implies when to use (when history is needed) but lacks a direct 'use X for current rates' statement.

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