Costa Rica Exchange Rate

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

With no annotations, the description carries the behavioral disclosure burden. It discloses the source ('certified by Hacienda') and the nature of the data (buy/sell USD and EUR reference), making it clear this is an official read-only lookup. It does not mention update cadence, but that is a minor gap for a zero-parameter tool.

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 tightly written sentences front-load the core purpose and add only relevant detail (Hacienda certification, invoicing use case). No 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 zero-parameter tool with an output schema present, the description is complete: it names the exact data (USD/EUR rates, buy/sell, EUR reference) and the authoritative source. The agent needs no additional info to select and call it 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 input schema has zero parameters, so there is nothing to disambiguate. Baseline is 4; the description's mention of specific currency pairs and buy/sell orientation complements the empty schema without needing parameter-level detail.

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 opens with a specific verb and resource: 'Get Costa Rica's official USD and EUR exchange rates (colón, CRC).' It further adds buy/sell for USD and EUR reference, certified by Hacienda, which clearly distinguishes this tool from generic exchange-rate or country-specific siblings.

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 explicitly states the intended application: 'used for invoicing and accounting in Costa Rica.' This gives clear context for when to call the tool, though it does not name alternative tools or explicitly state when not to use it.

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