forex_rate

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

The description lists return fields (current rate, change, high/low, 52-week range) but does not disclose that it is a read-only operation, nor mention rate limits, error conditions, or data frequency. Since no annotations exist, the description carries the full burden but falls short of comprehensive disclosure.

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 concise and well-structured: a one-line purpose, a list of return fields, an Args section, and five examples. Every sentence adds value, and the front-loading makes it easy to scan.

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 simplicity of the tool and the presence of an output schema, the description covers essential aspects. It lists return fields and provides usage examples. However, it lacks error handling details (e.g., invalid currency codes) and data source information.

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 description provides clear parameter semantics in the Args section (e.g., source and target currency codes with examples) and lists a default for to_currency. This compensates for the schema's lack of descriptions (0% coverage). Additional validation hints (like valid codes) could improve it.

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 tool's purpose: 'Get live forex exchange rate between two currencies.' It uses a specific verb and resource, and differentiates from sibling tools like stock_quote or crypto_price by focusing on forex.

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 (when you need forex rates), but does not explicitly state when not to use it or suggest alternative tools. No guidance on prerequisites or context.

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