Currency Historical Converter

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

Annotations already indicate idempotent, read-only, non-destructive behavior. The description adds that it returns exchange rate, original amount, and converted amount, providing transparency beyond the schema. No contradictions with annotations.

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 succinct sentences quickly convey purpose and use cases. No redundant or extraneous information. The main action is front-loaded.

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?

Given the tool's complexity (simple conversion), the description adequately covers purpose, usage context, and return values. No output schema exists, but the description specifies what is returned. Fully sufficient for an agent to invoke correctly.

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 covers 100% of parameter descriptions. The description adds no further detail about parameters beyond what the schema provides (e.g., currency codes, date format, amount defaults). Baseline score is appropriate as description does not compensate for any gaps.

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 converts an amount between currencies using a past date's exchange rate. It specifies the verb 'convert' and the resource 'amount from one currency to another', differentiating it from rate-only tools like currency_historical_rates or latest converter tools.

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 lists use cases (financial auditing, tax reporting, invoice reconciliation) which gives context but does not explicitly state when to use or avoid this tool versus siblings like currency_latest_converter or currency_historical_rates. No alternative tools or conditions are mentioned.

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