get_exchange_rate

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

The annotations already declare `readOnlyHint: true` and `destructiveHint: false`, covering safety aspects. However, the description adds no behavioral context beyond 'current', such as the data source, update frequency, or how rate values are calculated. For a read-only tool, this is minimal transparency.

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 of ten words. It is front-loaded with the verb 'Get' and immediately states the resource and scope, with no redundant information.

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?

This is a simple tool with a clear schema and good annotations. Without an output schema, the description could have explained the return format, but the operation is conventional enough that an agent can infer the response (a numeric rate). The overall context is sufficient for correct invocation, though slightly thin on response details.

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 input schema provides 100% coverage with clear descriptions for both `source` and `target` (including examples). The description does not add any additional parameter semantics, so it stays at the baseline of 3 for schema-heavy tools.

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 a clear resource 'current exchange rate' with the scope 'between two currencies'. It also distinguishes the tool from the sibling `get_exchange_rate_history` by emphasizing 'current', making the purpose unambiguous.

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 for retrieving current exchange rates, but does not explicitly state when to use it versus alternatives like `get_exchange_rate_history` or `create_quote`. No exclusions or prerequisites are mentioned, leaving the agent to infer the appropriate context.

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