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

Annotations already cover read-only, idempotent, non-destructive behavior. The description adds useful behavioral detail beyond those annotations: response is keyed by coin id, field names derive from the quote currency, and optional include flags control which extra fields appear. It does not discuss rate limits or the precision parameter, but the existing annotation coverage lowers the burden.

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 dense but well organized: purpose first, response behavior second, usage guidance and alternatives last. Every sentence carries operational value, and the alternatives are stated without excess wording.

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 simple read-only price lookup, the description covers output structure, flag behavior, when to use it, and sibling routing. The only material omission is precision, and since an output schema exists, the return-value burden is reduced. Overall it is nearly complete for correct tool selection and invocation.

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 low (29%), but the description compensates well: it clarifies ids and vs_currencies usage, explains how quote-currency field names are built, and maps each include flag to the corresponding output field. The only notable gap is the undocumented precision parameter, which is not mentioned in either the schema description or the tool description.

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 names a specific operation (price lookup by known CoinGecko ids and vs_currencies) and states the response shape: a map keyed by coin id. It also differentiates itself from sibling tools by pointing to get_coingecko_coins_markets for rank/supply/ATH data and get_coingecko_simple_token_price_id for contract addresses.

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?

It gives an explicit use condition: use whenever ids are already known and only current numbers are needed. It also names two concrete alternatives with their distinguishing conditions (rank/supply/ATH vs contract address), so an agent can route correctly without further inference.

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