Look up current foreign exchange rates between major world currencies. Returns exchange rate, bid/ask spread, and last update timestamp. Use for travel planning, international business transactions, or forex trading decisions.
| Name | Required | Description | Default |
|---|---|---|---|
| base | No | Base currency code for rate calculation (e.g. 'USD', 'EUR', 'GBP', 'JPY') | USD |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With annotations already declaring readOnlyHint and openWorldHint, the description still adds value by specifying the return fields: 'exchange rate, bid/ask spread, and last update timestamp.' It also emphasizes 'current' rates, reinforcing the dynamic nature of the data beyond what openWorldHint alone conveys.
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, with two sentences that front-load the purpose, then detail the returned data, and finally mention relevant use cases. No unnecessary words or repetition of schema 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?
For a simple read-only lookup tool with one optional parameter and no output schema, the description adequately covers the return fields and context. It could be slightly more specific about which currencies are supported, but 'major world currencies' is sufficient for typical use.
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 coverage is 100% and the single parameter 'base' is well-documented in the schema with default 'USD' and examples. The description adds minimal parameter-related meaning beyond 'major world currencies,' but the schema already carries the full weight, so the baseline of 3 is appropriate.
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 function: 'Look up current foreign exchange rates between major world currencies.' It names the resource (foreign exchange rates), specifies the verb (look up), and differentiates from sibling tools like crypto and stock by emphasizing 'major world currencies.'
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 provides explicit use cases: 'Use for travel planning, international business transactions, or forex trading decisions.' This gives clear context for when to use the tool, though it does not mention exclusions or directly compare to siblings like get_crypto_prices or get_stock_data.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
The tools are mostly distinct, but get_crypto_prices and track_crypto_portfolio both deal with cryptocurrency data, which could cause confusion. However, the descriptions clarify that one is for general price lookup and the other for portfolio tracking, so the overlap is manageable.
All tool names follow a consistent verb_noun pattern in snake_case: get_crypto_prices, get_exchange_rates, get_stock_data, screen_stocks, track_crypto_portfolio. There is no mixing of naming conventions.
With 5 tools, the server is well-scoped, covering crypto, forex, stocks, and screening without unnecessary bloat. The count is appropriate for the domain.
The server covers the main market data needs for crypto, forex, and equities, plus stock screening. Missing historical data or stock portfolio tracking are minor gaps that agents can work around.