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

Annotations declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the description need not repeat those. It does add context that the data comes from CoinGecko and includes live USD price, 24h change, and market cap. However, it does not mention that the symbol lookup may be case-insensitive (lightly covered by schema) or that prices may be delayed, nor does it disclose any rate limits or potential for unknown coins to return errors. With annotations covering safety, a 3 is fair.

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 longer than strictly necessary, especially the 'When to use' section which restates the same guidance already given. It is front-loaded with the key capability and returns, but the latter part could be trimmed. No wasted words about the tool itself, but the usage section is a bit repetitive.

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 description provides sufficient information: what it does, supported coins, return values, and when to use it. The output schema exists, so return format is covered. The main missing detail is error handling for unsupported coins, but that is not critical for an agent to call the tool correctly.

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?

The schema already describes the 'symbol' parameter well, listing example tickers and noting case-insensitivity, and coverage is 100%. The description adds the list of supported coins ('BTC, ETH, SOL, DOGE, BNB, XRP, MATIC, AVAX, ADA, LINK, and 100+ others') and specifies the return fields, which is helpful but not necessary for invoking the tool. The description does not introduce new syntax or format details 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 states the tool performs real-time cryptocurrency price lookup, lists specific supported coins (BTC, ETH, SOL, etc.), and specifies the returned data (live USD price, 24h change, market cap). It explicitly differentiates itself from market_pulse by saying 'Do NOT use market_pulse for specific coin prices — use this tool.' This leaves no ambiguity about the tool's purpose.

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?

Provides explicit 'When to use' and 'When not to use' sections, and explicitly names market_pulse as the alternative to avoid for specific coin prices. This is particularly strong guidance, as it directly tells the agent when to prefer this tool over a sibling.

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