compare

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

No annotations are present, so the description carries full responsibility for behavioral disclosure. It states the informational output, which is helpful, but it does not explicitly confirm the operation is read-only, mention authentication requirements beyond the api_key parameter, or disclose any rate limits, errors, or side effects. The 'compare' verb implies a safe operation, but this is under-specified.

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 two concise sentences, front-loaded with the primary action ('Compare...') and followed by a compact list of the displayed metrics. Every sentence adds value, with no redundant or filler content.

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?

The tool has a complete input schema and an output schema, so the description need not explain return values. It effectively covers the core function and the minimum coin count. It is slightly thin on usage guidance relative to siblings, but for a straightforward comparison tool with full schema coverage, it is adequately complete.

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%, so the baseline is 3. The description adds meaningful context by specifying 'two or more' for the coins parameter, a constraint not present in the schema (no minItems), and by clarifying the per-coin metrics returned. This goes beyond the schema's property descriptions.

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 uses a specific verb ('Compare') and resource ('cryptocurrencies'), and clearly indicates a side-by-side comparison of multiple coins. It also lists the exact metrics shown (price, market cap, 24h volume, 24h performance), which distinguishes it from sibling tools like price (single coin) or market_overview (broad market).

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 for comparing two or more cryptocurrencies, but it does not explicitly contrast with alternatives or state when not to use it. The phrase 'two or more' hints that it is not for single-coin queries, but no direct references to sibling tools are provided.

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