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

With no readOnly/destructive annotations, the description carries the burden and discloses key behaviors: ECB reference rates, historical dates back to 1999, and crypto pricing via USD. This is meaningful context beyond the title, though it omits potential failure modes or rate availability.

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 concise sentences; the first states purpose with an example, the second adds source, date range, and crypto behavior. No redundant words or repetition of schema descriptions.

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 simple conversion tool with four well-documented params and no output schema, the description covers purpose, rate source, date range, and crypto handling. It lacks only edge-case behavior like error handling or unsupported currencies, but overall is sufficient 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?

Schema already describes all four parameters, so baseline is 3. The description adds semantic value with the example and notes that date applies to currencies only and crypto converts through the dollar, which clarifies parameter interactions.

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 'Convert an amount from one currency to another' and provides a concrete example (250 GBP in JPY), clearly identifying this as a currency/asset conversion tool. It distinguishes from sibling tools like markets_list by specifying conversion behavior.

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 implies use for currency/asset conversion with ECB reference rates and crypto live pricing, but does not explicitly state when not to use it or name alternative tools. The context is clear enough for an agent to select it over list-type market tools.

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