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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered by structured data. The description adds genuinely new context beyond that: 'These are website snapshots,' warning the agent the data may be cached rather than real-time. It stops short of describing rate limits or refresh cadence, so not a full 5.

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?

Three sentences, front-loaded with the purpose and field list before pagination mechanics and routing. Every sentence carries distinct information and there is no filler.

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?

An output schema exists, so return-value details need not be explained, and annotations cover the read-only/open-world profile. The description supplies the remaining pieces an agent needs: what rows contain, pagination defaults and caps, the quote-currency selector, snapshot semantics, and sibling routing.

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 all three parameters are already documented in the schema. The description restates defaults (page=1, limit=100 capped at 100) and the role of vs_currency, adding minimal meaning beyond the schema, which is the baseline 3 case.

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?

States a specific verb (Browse) and resource (CoinGecko's paginated cryptocurrency market rows) and enumerates the fields returned (rank, price, market cap, volume, changes). It explicitly names the sibling tools it is not (coingecko_coin, coingecko_search), so an agent can distinguish it without opening any schema.

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?

Gives explicit routing: use coingecko_coin for a single coin's details or coingecko_search to find an identifier. It also flags that results are website snapshots, which is the key context for deciding whether to use this over a live-data sibling.

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