Rich crypto market data

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint as true/true/true/false, clearly indicating safe, read-only, non-destructive behavior. The description adds the pricing information ('$0.002 per call'), which is valuable cost disclosure. However, it does not disclose any behavioral traits beyond what annotations provide, such as rate limits, data freshness, or whether the response is paginated.

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 line that efficiently captures the tool's purpose and data points, followed by pricing. No filler or redundant information. 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?

Given that the tool has 2 parameters with 100% schema coverage, clear annotations, and no output schema requiring explanation, the description is complete. It lists the key data fields the user can expect (rank, 24h high/low, volume, all-time high) and mentions pricing. However, it omits any note about error cases or missing data (e.g., if coin IDs are invalid).

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% – both parameters (vs and ids) are described in the schema. The description adds the phrase 'Comma-separated CoinGecko coin ids' to clarify the format, which matches the schema's description. Since coverage is high, a baseline of 3 is appropriate; the description does not significantly deepen understanding beyond the schema.

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 identifies the tool as providing 'rich market data for one or more cryptocurrencies' and lists specific data points (rank, 24h high/low, volume, all-time high). This differentiates it from sibling tools like get_crypto_price (which likely only returns price) and get_crypto_trending (trending data). However, it doesn't explicitly state the exclusive differences from these siblings.

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 for fetching detailed market data but does not explicitly state when to use it versus alternatives like get_crypto_price or get_crypto_trending. No guidance on prerequisites, required format for coin IDs (though schema shows comma-separated), or scenarios where this tool is inappropriate.

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