Get Exchange Rate

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds some behavioral context by limiting the lookup to a specific symbol and date, but it does not disclose deeper traits such as the base currency or rate source. No contradiction with annotations exists.

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 a single focused sentence with no filler or redundancy. It front-loads the operation and the two key constraints, making it immediately scannable for an agent.

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, read-only, two-parameter tool with a complete input schema, output schema, and safety annotations, the description is nearly complete. The only minor gap is that the base currency or rate direction is not stated, but the output schema likely resolves this and it does not prevent correct invocation.

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 100%, and both 'symbol' and 'date' are fully documented in the input schema. The description only restates the parameters at a high level without adding format, constraints, or examples beyond what the schema already provides, so the baseline 3 applies.

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 uses a specific verb ('get') and names the resource ('exchange rate') with precise qualifiers: currency symbol and specific date. This clearly separates it from the sibling tools, none of which target exchange-rate retrieval.

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 the tool is used when you need a rate for a currency symbol on a particular date, but it does not explicitly state when to prefer it over sibling tools such as get_market_data or get_historical_data, nor does it mention exclusions. The context is clear but the guidance is not explicit enough for a 4.

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