Crypto price, 24h change, market cap

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is well-covered. The description adds the cost per call and specifies the exact data fields returned, which is useful context. However, it does not disclose rate limits, authentication requirements, or any edge cases (e.g., behavior for invalid IDs).

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?

Two sentences: first sentence states the purpose concisely, second sentence adds a critical cost note. No wasted words, front-loaded, and easy to parse.

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 tool is simple (2 params, no output schema) and annotations cover safety, the description is reasonably complete. It lists the output fields (price, 24h change, market cap) and the cost. However, it does not describe the return structure (e.g., object keys, data types) which would be helpful since there is no output schema.

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%, so the schema already documents both parameters (ids and vs_currency). The description does not add meaning beyond the schema; it mentions 'one or more cryptocurrencies' but that is implicit from the comma-separated ids. The cost note is not parameter-related. Baseline 3 applies as the schema carries the burden.

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 action ('current price, 24h change percent, and market cap') and resource ('cryptocurrencies'). It specifies the scope ('one or more'), making the purpose unambiguous. However, it does not differentiate from sibling tools like get_crypto_market_data or get_crypto_trending, which could overlap in intent.

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 includes a cost note ('Price: $0.001 per call') but provides no guidance on when to use this tool versus alternatives such as get_crypto_market_data or get_crypto_trending. There is no explicit mention of prerequisites, context, or exclusions.

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