crypto-fiat-price

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

With no annotations, the description carries full burden. It discloses that the upstream is CoinGecko public API (no key required) and states the return includes 'current price, 24h percent change per currency, and last updated timestamp.' This provides good behavioral insight, though rate limits or error handling are not mentioned.

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: three sentences with no wasted words. It is front-loaded with the core purpose, followed by examples, then context. Every sentence adds value.

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?

Without an output schema, the description explains the main return fields: current price, 24h percent change, and timestamp. However, it omits details on response format (e.g., JSON structure) and error handling if a coin is not found. For a simple tool, this is mostly complete but could be slightly more explicit.

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% with both parameters described. The description adds value by providing examples of coin names and currency codes, and specifies the default for currencies ('Default: usd,jpy,eur'), which goes beyond the schema alone.

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 with a specific verb and resource: 'Cryptocurrency price in any fiat currency.' It lists example currencies and coin names, and distinguishes from siblings by noting it is free and simple, with explicit comparison to 'specialized fiat oracles.'

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 context for when to use the tool, such as 'Asian/European market agents, cross-border DeFi pricing, and multi-currency portfolio valuation.' It hints at alternatives by stating '85% below specialized fiat oracles' but does not explicitly name sibling tools or state when not to use it.

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