Convert an amount between currencies

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

Annotations already cover readOnly and openWorld safety, so the bar is low; the description goes beyond them by disclosing the data source (ECB) and the return payload (converted amount plus the rate used). That is genuinely useful context, though it omits rate freshness/latency caveats.

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?

Three front-loaded sentences: purpose, return, example. No filler, and the most important information leads. The inline example is marginally redundant but cheap and clarifying.

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?

With no output schema, the description helpfully states what is returned (converted amount and rate used). Combined with the ECB source and a concrete call example, an agent has enough to invoke it correctly; the only real gap is the format of the optional 'on' date.

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 description coverage is 0%, so the description must carry the load. It effectively explains amount, base, and quote through the example and phrasing, and maps 'or a specific date' to the optional 'on' parameter, but never specifies the accepted date format for 'on'.

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 gives a specific verb and resource (convert a money amount between currencies) and even names the data source (latest ECB rate). It is clearly distinct from rate-listing siblings like latest_rates or historical_rate, though it never names an alternative explicitly.

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 'the latest ECB rate (or a specific date)', which implies the two usage modes, but there is no explicit when-to-use guidance, no prerequisites, and no routing to sibling tools like latest_rates or historical_rate. Usage is only implied.

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