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

Annotations already establish the tool as read-only, idempotent, non-destructive, and open-world. The description adds useful behavior beyond the schema: the exact data fields returned, the broad supported coin universe, and the CoinGecko ID compatibility. There is no contradiction with the annotations.

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 front-loaded with the core function and return values, then gives query examples and supported coins. The supported-coin list is long but serves a real disambiguation purpose for open-world crypto names, so it earns its place.

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?

For a single-parameter, read-only price lookup tool with no output schema, the description is complete: it states what is returned, how to phrase requests, and which coins are supported. Nothing essential is missing for an agent to select and invoke it 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?

Schema description coverage is 100%, so the baseline is 3, but the description adds meaningful value by listing many accepted coin names/tickers and noting that CoinGecko IDs are supported. This helps agents know what values can be passed beyond the few schema examples.

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 job: getting current price and market data for any cryptocurrency, with a concrete set of returned fields (USD price, 24h change, market cap, volume, all-time high). It is clearly about current price rather than comparison, history, or metadata, though it does not explicitly name or contrast sibling tools like crypto_compare or crypto_info.

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 gives explicit user-phrase examples ('what's the price of bitcoin?', 'solana price', 'BTC price') and states the general condition: any question about a specific coin's current value. It does not explicitly say when not to use it or mention alternatives, but the usage context is clear and practical.

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