exchangerate_latest

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

No annotations are provided, so the description carries full burden. It discloses that it uses the free tier and works without an API key, but it does not discuss rate limits, authentication requirements, or any potential side effects.

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 consists of two concise sentences with no wasted words, effectively communicating the core functionality and key usage note.

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 lack of an output schema, the description could hint at the response structure (e.g., rates for all currencies or just a subset) or mention supported currencies. It covers the basics but leaves some ambiguity about what exactly is returned.

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 coverage is 100%, so the schema already documents parameters. The description adds no additional meaning beyond 'works without API key' for the api_key parameter, which is already implied by the schema's optional nature.

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 'Get latest currency exchange rates for a base currency,' specifying the verb, resource, and scope. It is distinct from sibling tools like exchangerate_historical and exchangerate_convert.

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?

It mentions it works without an API key using the free tier, providing clear context for when to use it. However, it does not explicitly mention when not to use it or suggest alternatives for different needs (e.g., historical rates).

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