get_currency_rate

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively adds context beyond the input schema by specifying update frequency ('Updated every 4 hours') and access requirements ('Requires Starter plan or above'), which are crucial for understanding rate limits and authentication needs. It doesn't contradict any 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?

The description is front-loaded with the core purpose in the first sentence, followed by two concise sentences that add valuable context (update frequency and plan requirements). Every sentence earns its place with no wasted words, making it highly efficient and well-structured.

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 low complexity (1 parameter, no output schema, no annotations), the description is largely complete. It covers purpose, behavioral traits, and usage hints. However, it could be slightly more complete by explicitly mentioning the return value (e.g., exchange rate as a number) or error cases, though this is minor.

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 description coverage is 100%, with the parameter 'country_code' well-documented in the schema as an ISO2 or ISO3 code. The description adds no additional parameter semantics beyond what the schema provides, so it meets the baseline of 3 without compensating further.

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 specific action ('Get the live USD exchange rate') and resource ('for a country's currency'), distinguishing it from sibling tools like geolocate_ip or get_country that handle different data types. It precisely defines what the tool does without being vague or tautological.

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 implies usage context by mentioning 'live USD exchange rate' and 'Updated every 4 hours', suggesting when to use it for current rates. However, it lacks explicit guidance on when to choose this tool over alternatives (e.g., if historical rates are needed) or any exclusions, leaving some ambiguity.

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